How to validate phone numbers using regex

Question

I'm trying to put together a comprehensive regex to validate phone numbers. Ideally it would handle international formats, but it must handle US formats, including the following:

• 1-234-567-8901
• 1-234-567-8901 x1234
• 1-234-567-8901 ext1234
• 1 [phone]
• 1.234.567.8901
• 1/234/567/8901
• 12345678901

I'll answer with my current attempt, but I'm hoping somebody has something better and/or more elegant.

Medardas

This answer has been added to the Stack Overflow Regular Expression FAQ, under "Common Validation Tasks". – Ashby

Unfortunately, going to that page and searching for "Common Validation Tasks" yields no results... – Wretched

Is this a regex task? – Stile

In some cases, this is an XY Problem. You asked for a predicate which returns True if a phone number is valid, but you really just wanted a correct phone number. For anyone who is trying to sanitize phone numbers typed by end-users into a webpage or cellphone app, I recommend simply have 4 or 5 lines of code which goes left to right one character at a time and discards all non-numbers. [phone] becomes 3038739919. After deleting all non-numbers you can insert (dots .), insert (hyphens -) or slashes at the proper positions. – Heterodox

Answer 1

Better option... just strip all non-digit characters on input (except 'x' and leading '+' signs), taking care because of the British tendency to write numbers in the non-standard form +44 (0) ... when asked to use the international prefix (in that specific case, you should discard the (0) entirely).

Then, you end up with values like:

 12345678901
 12345678901x1234
 345678901x1234
 12344678901
 12345678901
 12345678901
 12345678901
 [phone]
 [phone]

Then when you display, reformat to your hearts content. e.g.

  1 [phone]
  1 [phone] x1234

Pahoehoe

The formatting code is going to be a waste of time if the numbers are allowed to come from outside the US. – Insubstantial

@Earwicker - agreed the formatting (if dealing with international #'s) should be smart enough to handle various formats... e.g. [phone] or [phone]. Depending how complex you want to get it should be something that can be figured out based on the number of digits and what the first few digits are. – Pahoehoe

This is good and all, but it doesn't validate what was entered was actually a phone number. For example, what if the user doesn't enter the requisite 10 digits? This should be combined with good regex validation. – Conjunction

string.replace("[^\d+!x]", "") – Pianissimo

jcmcbeth, why the !x part? This seems to suffice: [^\d+] rubular.com/r/aj32fRSSGK – Ohmmeter

@danilo - The !x is there to keep any "x" character from getting stripped so that extensions can be separated out. – Fusco

Considering the question was about validation - this is a really really bad answer. – Prurigo

@Prurigo I disagree. The original problem is trying to handle phone number validation because it was trying to handle all the possible formatting options. Rather than try to solve all that, take the input and "pre-strip" it of all formatting fluff until you have just the "number". Doing this solves 2 problems - testing the result is now easy and you can now ensure that values rendered back out for display can all be formatted consistently. The first comment on this answer about the "Complicator's Gloves" is a good read... sometimes the answer to a problem is to approach it differently. – Pahoehoe

For others who may be using the above [^\d+!x] - the exclamation point is unnecessary. Just use [^\d+x]. See #10340836. – Bookrack

@Raymond you can use $justDigitsOrPlusOrX = preg_replace("/[^\d+x]/", "", $phoneNum); to strip away all the chars you don't need... then test the remaining (if needed) – Pahoehoe

This works nicely, except in case of numbers like 1-800-CALL-NOW? – Austerlitz

@Austerlitz I suppose in those scenarios if that's what you really wanted you could enable a smart translation that would convert the letters to their matching numbers... but I think that's a very special corner case compared to what most folks are after. ;-) – Pahoehoe

Improvement on Regex above: /[^\d+x]|x(?=[^x]*x)/gi Prevents multiple x's (uses the last x in the string) – Marmara

@nashwan did you read the article linked in the first comment added by Nicholas Trandem the Original Question Poster? Sometimes (as you can see how the community has voted) even though there is a solution to use a 261 character regex that handles a bunch of scenarios... trying to attack the problem in a different manner is actually the answer you want. Note Dave Kirby's answer also suggests not using a strict regex... also gaining (ATM 79 upvotes) – Pahoehoe

@Austerlitz It's cute when people spell things out in the letter mappings that are on most phone keypads, but it's not encouraged in the standards. tools.ietf.org/html/rfc3966#section-5.1.2 – Diver

I should clarify that I would "store" the clean value, and only "decorate" it as needed for display later on. – Pahoehoe

You do need to be careful when presented with an number starting +44 (0) as well. This is a very common format in the UK, and you probably want to map it to +44 (i.e. remove the (0)). – Wadsworth

Yeah, validating or formatting phone numbers is not a good idea. The following are all valid German phone numbers: [phone], [phone]. If you're in Germany, you'd dial those as 089 12345 or 06221 1234, but from e.g. Switzerland it'd be 0049 89 12345 or 0049 6221 1234. So this is like the UK case, but our area codes don't have a fixed length. Unless you have a list, you can't format the numbers correctly. – Lamanna

How the hell is this such a highly voted answer? This doesn't validate anything. What's worse is all the other phone number validation questions reference this one... – Stranger

@Stranger it may not validate a phone number, but it offers an alternate solution that is more reliable than trying to divine whether a given phone number is valid - considering that the idea of valid differs significantly between countries. IMO it's a good solution, while I agree it doesn't validate it still solves the problem. – Abrasion

@configurator Well, country dialing codes have the prefix property, so your example (4 (420) 778-457800) if 4 is the country code and 420 is an area/city code) could not be a real number, however your point that the "+" is important to designate whether the first number(s) are a country code stands -- maybe a better example would be – Felipa

Does not use regular expressions. +1 – Involve

See also : technet.microsoft.com/en-us/library/cc728034(v=ws.10).aspx If using TAPI to dial on windows this may help. – Nealson

I created a public gist providing an ES6 function building on the regex @AlbertBori provided. Feedback welcomed. – Digitalize

Answer 2

.*

If the users want to give you their phone numbers, then trust them to get it right. If they do not want to give it to you then forcing them to enter a valid number will either send them to a competitor's site or make them enter a random string that fits your regex. I might even be tempted to look up the number of a premium rate horoscope hotline and enter that instead.

I would also consider any of the following as valid entries on a web site:

"123 456 7890 until 6pm, then 098 765 4321"  
"123 456 7890 or try my mobile on 098 765 4321"  
"ex-directory - mind your own business"

Fried

I agree with the sentiment here, but sometimes it's nice to perform validation when the phone number is actually going to be used for something important in the interest of the user. Best example here is credit card authorization for a purchase. If the phone number is wrong, the auth might fail. – Compellation

If the user doesn't want to enter his phone number you can just allow the field to be optional, but is it to much to ask the user to enter a valid phone number if they are going to enter one? – Pianissimo

Also a role of validation is simply to remind people to add area codes etc that they might not otherwise remember to add, but which cannot possibly be guessed after the fact. – Patrilocal

I usually tend to gravitate towards this way of thinking with user experience. A valid US phone number at the core is 10 digits: ^(.*\d.*){10,}$. That allows it to be entered in any way the user would like. Then, on the backend, strip out invalid characters. – Brinker

@Compellation But regex validation won't help you. The one and the only way to actually validate if the phone number is correct is to actually send a message to it (in case of mobile) AND make sure the user confirms using some kind of verification code. This is what you do when the number correctness is important. Everything else is just for user's convenience to protect against some (but not all) typos and does not validate anything. – Palaestra

@AlexB well sure, I understand that, but if you can help me catch the error of leaving off a digit, it saves me the (slight) inconvenience of getting a server-side error, interpreting it, finding the field again, etc. – Compellation

There are a million use cases where this plain text solution is the answer. But there are a million use cases where this would cause many many problems. Look at how you are using the phone number and why you are asking for it. Then you can decide which methodology is right for you. If you don't know why you are asking or how you are using it, you probably shouldn't be asking for a phone number in the first place. – Amoebaean

True, but then you could just do something along the lines of 'when is not empty, validate'. Something like if (!empty($telephone) && !validation_function($telephone)) { //throw_error } then you can choose NOT to input your number. – Vergne

Cool. My phone number is 1' OR 1=1 -- PWNED. See xkcd.com/327 and owasp.org/index.php/Testing_for_SQL_Injection_(OWASP-DV-005) – Verena

@AaronNewton: performing validation at the form level or using regexes is unsafe anyway, there are better ways to prevent sql injection. – Martinemartineau

@CommuSoft that's completely true. However, a better statement might be don't rely solely on regex for prevention of SQL injection. I would still argue that it makes sense to check for obviously wrong or nefarious input, e.g. can you think of a case where a phone number needs anything other than alpha-numerics + basic punctuation, or needs to be longer than the length of the field in the database? Regarding the latter, it is likely to confuse and or annoy the user if the database field is 128 characters but you allow the user to enter 129 characters, resulting in some error on the UI. – Verena

This response is irreverent and in no way relevant to the question. The OP asked for help validating the format of input from a user; not for your personal opinion about whether he should. Potential use case: The website is for a company's internal usage - not meaning intranet usage, but rather this company has employees that work "out in the field" and communicate with in-office employees via this website. They need the person to enter a valid phone number at which they can be reached, as part of their job requirements, and want to avoid simple mistakes that could cause headaches. – Leucocyte

This is extremely unhelpful for any case in which a phone number is needed for automated purposes, for example sms validation codes. You can't and shouldn't trust the user to get their phone number right with no validation. – Inessive

Answer 3

It turns out that there's something of a spec for this, at least for North America, called the NANP.

You need to specify exactly what you want. What are legal delimiters? Spaces, dashes, and periods? No delimiter allowed? Can one mix delimiters (e.g., +0.111-222.3333)? How are extensions (e.g., 111-222-3333 x 44444) going to be handled? What about special numbers, like 911? Is the area code going to be optional or required?

Here's a regex for a 7 or 10 digit number, with extensions allowed, delimiters are spaces, dashes, or periods:

^(?:(?:\+?1\s*(?:[.-]\s*)?)?(?:\(\s*([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9])\s*\)|([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9]))\s*(?:[.-]\s*)?)?([2-9]1[02-9]|[2-9][02-9]1|[2-9][02-9]{2})\s*(?:[.-]\s*)?([0-9]{4})(?:\s*(?:#|x\.?|ext\.?|extension)\s*(\d+))?$

Pettiford

here it is without the extension section (I make my users enter ext in a separate field): ^(?:(?:\+?1\s*(?:[.-]\s*)?)?(?:(\s*([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9])\s*)|([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9]))\s*(?:[.-]\s*)?)?([2-9]1[02-9]|[2-9][02-9]1|[2-9][02-9]{2})\s*(?:[.-]\s*)?([0-9]{4})$ – Tasman

This worked nicely for me. I needed to update the extension part though by adding a slash before the #, otherwise it says from there over is a comment – Bandoleer

What about adding "(" and ")" to that list of delimiters? – Hundley

Here is a version that only matches 10 digit phone numbers (not 7 digit like 843-1212): /(?:(?:\+?1\s*(?:[.-]\s*)?)?(?:(\s*([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9])\s*)|([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9]))\s*(?:[.-]\s*)?)([2-9]1[02-9]|[2-9][02-9]1|[2-9][02-9]{2})\s*(?:[.-]\s*)?([0-9]{4})/ – Dendritic

10 digit accepts () around area code, and dosen't allow preceeding 1 as country code (?:(?:(\s*\(?([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9])\s*)|([2-9]1[02-9]|[2-9][02-8]1|[2-9][02-8][02-9]))\)?\s*(?:[.-]\s*)?)([2-9]1[02-9]|[2-9][02-9]1|[2-9][02-9]{2})\s*(?:[.-]\s*)?([0-9]{4}) – Colourable

@StevenSoroka I have had Jeffrey Friedl's book beside me on my desk for the past two years, as regular expressions are a major part of my work. It takes a good while to really understand regular expressions. Sometimes, the readers of this site are simply looking for an existing soltuion, rather than writing their own, especially in domains with lots of corner cases, such as phone number representations. – Redbud

@Pettiford I understand that, but majority of the responses here are "me too" type of one-off regular expressions that likely don't fit any of your corner cases. These then end up on all the websites I'm trying to use and I can't enter my zip code or phone number or email address because someone used a half-baked regular-expression (eg: + is a valid character in email addresses). The best responses on this page point users to libraries, not to napkin-scrawled regexes. – Jaqitsch

Be careful to check for non-breaking spaces when copying these expressions. – Forked

I wonder if something changed since you first posted this. It doesn't match at least one valid area code: 410 (Maryland). 410 is mentioned in the Wikipedia article you linked to, but 410 has been in service since 1991. – Iffy

This seems to work with every scenario I put in.. I even put an invalid area code, for example an area code that starts with 1 is invalid and it caught it. AAA+++ Perfection for USA Phone Numbers.. – Santamaria

An example of where this regex fails: 866-411-1234 (because it does not allow a 411 exchange per NANPA rules, but these are okay on 8xx numbers). regex101.com/r/3DSYIr/1 – Lohman

Answer 4

I would also suggest looking at the "libphonenumber" Google Library. I know it is not regex but it does exactly what you want.

For example, it will recognize that:

15555555555

is a possible number but not a valid number. It also supports countries outside the US.

Highlights of functionality:

• Parsing/formatting/validating phone numbers for all countries/regions of the world.
• getNumberType - gets the type of the number based on the number itself; able to distinguish Fixed-line, Mobile, Toll-free, Premium Rate, Shared Cost, VoIP and Personal Numbers (whenever feasible).
• isNumberMatch - gets a confidence level on whether two numbers could be the same.
• getExampleNumber/getExampleNumberByType - provides valid example numbers for all countries/regions, with the option of specifying which type of example phone number is needed.
• isPossibleNumber - quickly guessing whether a number is a possible phonenumber by using only the length information, much faster than a full validation.
• isValidNumber - full validation of a phone number for a region using length and prefix information.
• AsYouTypeFormatter - formats phone numbers on-the-fly when users enter each digit.
• findNumbers - finds numbers in text input.
• PhoneNumberOfflineGeocoder - provides geographical information related to a phone number.

Examples

The biggest problem with phone number validation is it is very culturally dependant.

• America
  • (408) 974–2042 is a valid US number
  • (999) 974–2042 is not a valid US number
• Australia
  • 0404 999 999 is a valid Australian number
  • [phone] is also a valid Australian number
  • [phone] is not a valid Australian number

A regular expression is fine for checking the format of a phone number, but it's not really going to be able to check the validity of a phone number.

I would suggest skipping a simple regular expression to test your phone number against, and using a library such as Google's libphonenumber (link to GitHub project).

Introducing libphonenumber!

Using one of your more complex examples, 1-234-567-8901 x1234, you get the following data out of libphonenumber (link to online demo):

Validation Results

Result from isPossibleNumber()  true
Result from isValidNumber()     true

Formatting Results:

E164 format                    [phone]
Original format                [phone] ext. 123
National format                [phone] ext. 123
International format           [phone] ext. 123
Out-of-country format from US  1 [phone] ext. 123
Out-of-country format from CH  00 1 234-567-8901 ext. 123

So not only do you learn if the phone number is valid (which it is), but you also get consistent phone number formatting in your locale.

As a bonus, libphonenumber has a number of datasets to check the validity of phone numbers, as well, so checking a number such as [phone] (the international version of [phone]) returns as a valid number with formatting:

Validation Results

Result from isPossibleNumber()  true
Result from isValidNumber()     true

Formatting Results

E164 format                    [phone]
Original format                61 2 9999 9999
National format                [phone]
International format           [phone]
Out-of-country format from US  011 61 2 9999 9999
Out-of-country format from CH  00 61 2 9999 9999

libphonenumber also gives you many additional benefits, such as grabbing the location that the phone number is detected as being, and also getting the time zone information from the phone number:

PhoneNumberOfflineGeocoder Results
Location        Australia

PhoneNumberToTimeZonesMapper Results
Time zone(s)    [Australia/Sydney]

But the invalid Australian phone number ([phone]) returns that it is not a valid phone number.

Validation Results

Result from isPossibleNumber()  true
Result from isValidNumber()     false

Google's version has code for Java and Javascript, but people have also implemented libraries for other languages that use the Google i18n phone number dataset:

• PHP: https://github.com/giggsey/libphonenumber-for-php
• Python: https://github.com/daviddrysdale/python-phonenumbers
• Ruby: https://github.com/sstephenson/global_phone
• C#: https://github.com/twcclegg/libphonenumber-csharp
• Objective-C: https://github.com/iziz/libPhoneNumber-iOS
• JavaScript: https://github.com/ruimarinho/google-libphonenumber
• Elixir: https://github.com/socialpaymentsbv/ex_phone_number

Unless you are certain that you are always going to be accepting numbers from one locale, and they are always going to be in one format, I would heavily suggest not writing your own code for this, and using libphonenumber for validating and displaying phone numbers.

Grau

Noting that there is now also Go port at: github.com/ttacon/libphonenumber – Nmr

When checking if it's a possible number don't you need to specify a country code? I'm using the PHP version and if I enter a British number like (replace 0's with real numbers) 07700000000 I get Missing or invalid default region. error. But if I specify the country code it will pass. – Delcine

@Delcine (and anyone who comes across this question and wonders the same) when parsing a number, you can specify the expected region, and the library will look for non-international numbers in that region. If you don't specify, it will reject anything not in a valid international format. – Kettle

Consider github.com/nyaruka/phonenumbers as it has become the "official" Go package recommended by Google rather than libphonenumber. – Toughen

I can confirm what @Delcine says. Took time to get there, but the result is exactly as expected - local numbers accepted in any format plus all fully specified international formats. – Glochidiate

"I know it is not regex but it does" It does RegExp under the hood actually, a lot. Worth reading about misbeliefs regarding phone number validation: github.com/google/libphonenumber/blob/master/FALSEHOODS.md The problem with the npm port that it takes >500kB to bundle it in your frontend app. Given the complexity, I would consider using specialised services, like validatephonenumber.com – Swank

Answer 5

/^(?:(?:\(?(?:00|\+)([1-4]\d\d|[1-9]\d*)\)?)[\-\.\ \\\/]?)?((?:\(?\d{1,}\)?[\-\.\ \\\/]?)+)(?:[\-\.\ \\\/]?(?:#|ext\.?|extension|x)[\-\.\ \\\/]?(\d+))?$/i

This matches:

 - ([phone]
 - 90191919908
 - 555-8909
 - 001 6867684
 - 001 6867684x1
 - 1 [phone]
 - 1-234-567-8901 x1234
 - 1-234-567-8901 ext1234
 - 1-234 567.89/01 ext.1234
 - 1(234)5678901x1234
 - (123)8575973
 - (0055)(123)8575973
 - [phone]

On $n, it saves:

1. Country indicator
2. Phone number
3. Extension

You can test it on https://regex101.com/r/kFzb1s/42

Turcotte

This was the most comprehensive regex I've seen. It's easy to get around until you remove ^ and $ or else I'm able to get around it using [111] [111] [1111] or 111--111--1111 and the like. (sorry, deleted my last comment) – Hennahane

Can you please re-phrase? I can't understand this: "It's easy to get arround until you remove ^ and $ or else I'm able to get around it using [111] [111] [1111]". Does it mean that it validates '[111] [111] [1111]' when you take the ^ and the $? – Turcotte

I got around your regex using [111] [111] [1111] and 111--111--1111 until I removed ^ and $ from the regex. – Hennahane

As I asked before, which engine are you using? 111-111-1111 validates perfectly (syntactically, the second one is valid) while [111] [111] [1111] doesn't validate (as expected) – Turcotte

gethifi.com/tools/regex and I meant 111--111--1111 as mentioned above. – Hennahane

111--111--1111 is invalid: i62.tinypic.com/2rnhr7k.png (perfectly fine) and [111] [111] [1111] is also invalid: i58.tinypic.com/9ru64y.png (as expected) – Turcotte

let us continue this discussion in chat – Hennahane

^^^This is a great example of why comment threads should NOT go to chat. I am very interested in how this conversation turned out and need to know if this ReGex is sturdy enough to use in my app. Unfortunately, the chat conversation is now gone. – Bronze

To be honest, i didnt went to chat. After asking multiple times for explainations, i was left with no info. You can always try it yourself with all kind of numbers you find online, in multiple formats. One thing i tried with this one is to use multiple phone numbers, but it doesnt work that well if they have spaces around. And i have to find a solution to count the amount of digits and enforce a specific amount. – Turcotte

How do I make this so it can extract the number from a string, anywhere that the phone number may be? – Gujarati

@Gujarati Remove the ^ and the $, and it should work with lots of false positives. – Turcotte

@Gujarati That's expected. You're trying to make a Javascript RegExp work on PHP with PCRE. You need to slightly re-write it. Which is outside the scope of this question. Using regex101.com, pasting the regex there and going to "tools" -> "code generator", you get this: /(?:(?:\(?(?:00|\+)([1-4]\d\d|[1-9]\d?)\)?)?[\-\.\ \\\\\/]?)?((?:\(?\d{1,}\)?[\-\.\ \\\\\/]?){0,})(?:[\-\.\ \\\\\/]?(?:#|ext\.?|extension|x)[\-\.\ \\\\\/]?(\d+))?/i. And this one works. – Turcotte

I was playing with some random numbers and found out that this regex will accept phone numbers starting with /,whitespace and - . isn't that wrong? – Apgar

@Apgar Thank you for pointing it out, I managed to fix it. Additionally, I've added a different link with unit tests, to make sure it worked as it should. The bug was a single ? that shouldn't be there. – Turcotte

This doesn't seem to match the USA country code. For example [phone] – Composition

@Composition I've edited it to match +1 as well. The problem is that I was assuming that the indicative was 1 ot 9 and then 1 or more numbers, but USA uses +1, which breaks the "1 or more numbers". It works now for those. – Turcotte

Answer 6

Although the answer to strip all whitespace is neat, it doesn't really solve the problem that's posed, which is to find a regex. Take, for instance, my test script that downloads a web page and extracts all phone numbers using the regex. Since you'd need a regex anyway, you might as well have the regex do all the work. I came up with this:

1?\W*([2-9][0-8][0-9])\W*([2-9][0-9]{2})\W*([0-9]{4})(\se?x?t?(\d*))?

Here's a perl script to test it. When you match, $1 contains the area code, $2 and $3 contain the phone number, and $5 contains the extension. My test script downloads a file from the internet and prints all the phone numbers in it.

#!/usr/bin/perl

my $us_phone_regex =
        '1?\W*([2-9][0-8][0-9])\W*([2-9][0-9]{2})\W*([0-9]{4})(\se?x?t?(\d*))?';


my @tests =
(
"1-234-567-8901",
"1-234-567-8901 x1234",
"1-234-567-8901 ext1234",
"1 [phone]",
"1.234.567.8901",
"1/234/567/8901",
"12345678901",
"not a phone number"
);

foreach my $num (@tests)
{
        if( $num =~ m/$us_phone_regex/ )
        {
                print "match [$1-$2-$3]\n" if not defined $4;
                print "match [$1-$2-$3 $5]\n" if defined $4;
        }
        else
        {
                print "no match [$num]\n";
        }
}

#
# Extract all phone numbers from an arbitrary file.
#
my $external_filename =
        'http://web.textfiles.com/ezines/PHREAKSANDGEEKS/PnG-spring05.txt';
my @external_file = `curl $external_filename`;
foreach my $line (@external_file)
{
        if( $line =~ m/$us_phone_regex/ )
        {
                print "match $1 $2 $3\n";
        }
}

Edit:

You can change \W* to \s*\W?\s* in the regex to tighten it up a bit. I wasn't thinking of the regex in terms of, say, validating user input on a form when I wrote it, but this change makes it possible to use the regex for that purpose.

'1?\s*\W?\s*([2-9][0-8][0-9])\s*\W?\s*([2-9][0-9]{2})\s*\W?\s*([0-9]{4})(\se?x?t?(\d*))?';

Sternwheeler

FYI the regex also matches: (4570457-6789 which would be a pretty common typo. The match groups get skewed too: rubular.com/r/TaTP0mHL5c – Ornelas

@Ornelas Prepending (^|[^\d\n]) (with multiline flag on) avoids the general problem, by ensuring it's not immediately preceded by something numeric. – Fluxmeter

Note that this is North America-centric -- it misses "44 7911 123456" – Whitt

Answer 7

I answered this question on another SO question before deciding to also include my answer as an answer on this thread, because no one was addressing how to require/not require items, just handing out regexs: Regex working wrong, matching unexpected things

From my post on that site, I've created a quick guide to assist anyone with making their own regex for their own desired phone number format, which I will caveat (like I did on the other site) that if you are too restrictive, you may not get the desired results, and there is no "one size fits all" solution to accepting all possible phone numbers in the world - only what you decide to accept as your format of choice. Use at your own risk.

Quick cheat sheet

• Start the expression: /^
• If you want to require a space, use: [\s] or \s
• If you want to require parenthesis, use: [(] and [)] . Using \( and \) is ugly and can make things confusing.
• If you want anything to be optional, put a ? after it
• If you want a hyphen, just type - or [-] . If you do not put it first or last in a series of other characters, though, you may need to escape it: \-
• If you want to accept different choices in a slot, put brackets around the options: [-.\s] will require a hyphen, period, or space. A question mark after the last bracket will make all of those optional for that slot.
• \d{3} : Requires a 3-digit number: 000-999. Shorthand for [0-9][0-9][0-9].
• [2-9] : Requires a digit 2-9 for that slot.
• (\+|1\s)? : Accept a "plus" or a 1 and a space (pipe character, |, is "or"), and make it optional. The "plus" sign must be escaped.
• If you want specific numbers to match a slot, enter them: [246] will require a 2, 4, or 6. (?:77|78) or [77|78] will require 77 or 78.
• $/ : End the expression

Bruton

This is very useful, but I doubt and looking for a {min,max} expression. Can you help? – Tribute

If it is a single digit we're talking about (and you can make it match according to that), see the [2-9] block I put there. That means your min is 2, and your max is 9. Adjust accordingly. – Bruton

Answer 8

I wrote simpliest (although i didn't need dot in it).

^([0-9\(\)\/\+ \-]*)$

As mentioned below, it checks only for characters, not its structure/order

Oncoming

this validates tons of numbers that are technically invalid. like, "-- +()()())())))". Learn to read regular expressions so you can understand what you're doing. – Jaqitsch

@StevenSoroka technically it may allow lot of invalid cases, but when we think about just helping the user out to avoid common mistakes with the simplest possible solution, this is the way to go :) – Forsake

this also matching white space, empty line – Kado

@HappyHardik. Indeed. Simple and powerful, for basic validation let the user type more than one dot, dash, bracket or plus. – Homeopathic

Just used it and it's wrong in many aspects. For example, a UK phone number may begin with +44, or a phone nuber may have (0) inside it. But this is not valid according to your regular expression. I would recommend @Ismael Miguel's answer. It works just fine and I would recommend you to revise your answer. – Shortcut

Answer 9

Note that stripping () characters does not work for a style of writing UK numbers that is common: [phone] which means dial either the international number:
[phone]
or in the UK dial 01234567890

Sensualism

See also International notation of UK numbers – Precedent

Answer 10

If you just want to verify you don't have random garbage in the field (i.e., from form spammers) this regex should do nicely:

^[0-9+\(\)#\.\s\/ext-]+$

Note that it doesn't have any special rules for how many digits, or what numbers are valid in those digits, it just verifies that only digits, parenthesis, dashes, plus, space, pound, asterisk, period, comma, or the letters e, x, t are present.

It should be compatible with international numbers and localization formats. Do you foresee any need to allow square, curly, or angled brackets for some regions? (currently they aren't included).

If you want to maintain per digit rules (such as in US Area Codes and Prefixes (exchange codes) must fall in the range of 200-999) well, good luck to you. Maintaining a complex rule-set which could be outdated at any point in the future by any country in the world does not sound fun.

And while stripping all/most non-numeric characters may work well on the server side (especially if you are planning on passing these values to a dialer), you may not want to thrash the user's input during validation, particularly if you want them to make corrections in another field.

Jackinthebox

Answer 11

Here's a wonderful pattern that most closely matched the validation that I needed to achieve. I'm not the original author, but I think it's well worth sharing as I found this problem to be very complex and without a concise or widely useful answer.

The following regex will catch widely used number and character combinations in a variety of global phone number formats:

/^\s*(?:\+?(\d{1,3}))?([-. (]*(\d{3})[-. )]*)?((\d{3})[-. ]*(\d{2,4})(?:[-.x ]*(\d+))?)\s*$/gm

Positive:
+42 555.123.4567
[phone]
[phone]
[phone]
(926) 1234567
[phone]
926 1234567
9261234567
1234567
123-4567
123-89-01
495 1234567
469 123 45 67
89261234567
8 (926) 1234567
926.123.4567
415-555-1234
650-555-2345
[phone]
202 555 4567
4035555678
1 416 555 9292

Negative:
926 3 4
8 800 600-APPLE

Original source: http://www.regexr.com/38pvb

Wiggs

This has some limited support for extensions. It matches "616-555-1234 x567" but not "616-555-1234 ext. 567". – Blockbuster

False positive for e.g."-------((((((55555555" or "99999999999999999999999" – Alexine

It does not validate Nitherland macdonalds number [phone] (I was just testing for random numbers) – Conchiolin

Answer 12

My attempt at an unrestrictive regex:

/^[+#*\(\)\[\]]*([0-9][ ext+-pw#*\(\)\[\]]*){6,45}$/

Accepts:

+(01) 123 (456) 789 ext555
123456
*44 123-456-789 [321]
123456
123456789012345678901234567890123456789012345
*****++[](][((( 123456tteexxttppww

Rejects:

mob [phone]
1234 567 890 after 5pm
john smith
(empty)
1234567890123456789012345678901234567890123456
911

It is up to you to sanitize it for display. After validating it could be a number though.

Shaunda

Answer 13

Have you had a look over at RegExLib?

Entering US phone number brought back quite a list of possibilities.

Xavler

This looks like a great way to integrate obscure bugs into your code. – Putnem

Link-only answers should be avoided because they may break in the future and render the post useless. Static solutions are always necessary to sustain the value of an answer. If you wanted to recommend a hyperlink, add it as a comment under the question. – Jameejamel

Answer 14

I found this to work quite well:

^\(*\+*[1-9]{0,3}\)*-*[1-9]{0,3}[-. /]*\(*[2-9]\d{2}\)*[-. /]*\d{3}[-. /]*\d{4} *e*x*t*\.* *\d{0,4}$

It works for these number formats:

1-234-567-8901
1-234-567-8901 x1234
1-234-567-8901 ext1234
1 [phone]
1.234.567.8901
1/234/567/8901
12345678901
1-234-567-8901 ext. 1234
([phone]

Make sure to use global AND multiline flags to make sure.

Link: http://www.regexr.com/3bp4b

Errolerroll

Answer 15

This is a simple Regular Expression pattern for Philippine Mobile Phone Numbers:

((\+[0-9]{2})|0)[.\- ]?9[0-9]{2}[.\- ]?[0-9]{3}[.\- ]?[0-9]{4}

or

((\+63)|0)[.\- ]?9[0-9]{2}[.\- ]?[0-9]{3}[.\- ]?[0-9]{4}

will match these:

+63.917.123.4567  
[phone]  
[phone]  
[phone]  
09171234567  

The first one will match ANY two digit country code, while the second one will match the Philippine country code exclusively.

Hardfeatured

Thanks. How about landline numbers with area code such as 028231234? I'm wondering if area codes are only 2-3 digit numbers and are they always preceded by 0? – Tananarive

how to validate for canada – Showiness

Answer 16

If you're talking about form validation, the regexp to validate correct meaning as well as correct data is going to be extremely complex because of varying country and provider standards. It will also be hard to keep up to date.

I interpret the question as looking for a broadly valid pattern, which may not be internally consistent - for example having a valid set of numbers, but not validating that the trunk-line, exchange, etc. to the valid pattern for the country code prefix.

North America is straightforward, and for international I prefer to use an 'idiomatic' pattern which covers the ways in which people specify and remember their numbers:

^((((\(\d{3}\))|(\d{3}-))\d{3}-\d{4})|(\+?\d{2}((-| )\d{1,8}){1,5}))(( x| ext)\d{1,5}){0,1}$

The North American pattern makes sure that if one parenthesis is included both are. The international accounts for an optional initial '+' and country code. After that, you're in the idiom. Valid matches would be:

• (xxx)xxx-xxxx
• (xxx)-xxx-xxxx
• (xxx)xxx-xxxx x123
• 12 1234 123 1 x1111
• 12 12 12 12 12
• 12 1 1234 123456 x12345
• [phone]
• [phone]
• [phone]
• [phone]

This may be biased as my experience is limited to North America, Europe and a small bit of Asia.

Windtight

I've been trying to implement the above in my javascript validation script but I keep getting an invalid quantifier error. Any ideas on what I'm doing wrong? – Lignify

I'd add the trivial case where the phone is specified without symbols but maybe spaces and country code, in Europe is typical for local and mobile numbers: 676412342, 676 46 32 12, 676 463 212 – Hardhearted

Answer 17

Here's my best try so far. It handles the formats above but I'm sure I'm missing some other possible formats.

^\d?(?:(?:[\+]?(?:[\d]{1,3}(?:[ ]+|[\-.])))?[(]?(?:[\d]{3})[\-/)]?(?:[ ]+)?)?(?:[a-zA-Z2-9][a-zA-Z0-9 \-.]{6,})(?:(?:[ ]+|[xX]|(i:ext[\.]?)){1,2}(?:[\d]{1,5}))?$

Medardas

Worked like a charm! Thanks for sharing – Rotogravure

Answer 18

My gut feeling is reinforced by the amount of replies to this topic - that there is a virtually infinite number of solutions to this problem, none of which are going to be elegant.

Honestly, I would recommend you don't try to validate phone numbers. Even if you could write a big, hairy validator that would allow all the different legitimate formats, it would end up allowing pretty much anything even remotely resembling a phone number in the first place.

In my opinion, the most elegant solution is to validate a minimum length, nothing more.

Teratogenic

After trying a number of these and going through the existing data and feedback from users i would tend to agree... – Virgievirgil

Sometimes you need to do validation though. If I'm sending out confirmation codes I can't just send a code to any random garbage a spammer has input in the field. I want to make sure the number is probably a phone number before wasting resources messaging it. – Weekly

Answer 19

You'll have a hard time dealing with international numbers with a single/simple regex, see this post on the difficulties of international (and even north american) phone numbers.

You'll want to parse the first few digits to determine what the country code is, then act differently based on the country.

Beyond that - the list you gave does not include another common US format - leaving off the initial 1. Most cell phones in the US don't require it, and it'll start to baffle the younger generation unless they've dialed internationally.

You've correctly identified that it's a tricky problem...

-Adam

Meso

Not an offered solution. IT IS POSSIBLE. Just because it's tricky or complex doesn't mean you should just throw your arms up. – Sargent

Answer 20

After reading through these answers, it looks like there wasn't a straightforward regular expression that can parse through a bunch of text and pull out phone numbers in any format (including international with and without the plus sign).

Here's what I used for a client project recently, where we had to convert all phone numbers in any format to tel: links.

So far, it's been working with everything they've thrown at it, but if errors come up, I'll update this answer.

Regex:

/(\+*\d{1,})*([ |\(])*(\d{3})[^\d]*(\d{3})[^\d]*(\d{4})/

PHP function to replace all phone numbers with tel: links (in case anyone is curious):

function phoneToTel($number) {
    $return = preg_replace('/(\+*\d{1,})*([ |\(])*(\d{3})[^\d]*(\d{3})[^\d]*(\d{4})/', '<a href="tel:$1$3$4$5">$1 ($3) $4-$5</a>', $number); // includes international
    return $return;
}

Poplar

This regular expression matched +1 1234562222222222222222222222. – Unveil

why not just return? – Drat

False positive for "999999999999999999999999999999999999999" – Whitt

Answer 21

I believe the Number::Phone::US and Regexp::Common (particularly the source of Regexp::Common::URI::RFC2806) Perl modules could help.

The question should probably be specified in a bit more detail to explain the purpose of validating the numbers. For instance, 911 is a valid number in the US, but 911x isn't for any value of x. That's so that the phone company can calculate when you are done dialing. There are several variations on this issue. But your regex doesn't check the area code portion, so that doesn't seem to be a concern.

Like validating email addresses, even if you have a valid result you can't know if it's assigned to someone until you try it.

If you are trying to validate user input, why not normalize the result and be done with it? If the user puts in a number you can't recognize as a valid number, either save it as inputted or strip out undailable characters. The Number::Phone::Normalize Perl module could be a source of inspiration.

Energetic

I'm going to go out on a limb here and say that allowing 911 as a phone number is probably a bad idea in almost all applications of this regex. Good catch though. – Heirship

Answer 22

Do a replace on formatting characters, then check the remaining for phone validity. In PHP,

 $replace = array( ' ', '-', '/', '(', ')', ',', '.' ); //etc; as needed
 preg_match( '/1?[0-9]{10}((ext|x)[0-9]{1,4})?/i', str_replace( $replace, '', $phone_num );

Breaking a complex regexp like this can be just as effective, but much more simple.

Heid

Answer 23

I work for a market research company and we have to filter these types of input alllll the time. You're complicating it too much. Just strip the non-alphanumeric chars, and see if there's an extension.

For further analysis you can subscribe to one of many providers that will give you access to a database of valid numbers as well as tell you if they're landlines or mobiles, disconnected, etc. It costs money.

Sirajuddaula

Validation? 123%$)*%()$*()#456*()*$#(*(#$@8908 would match your proposed solution. – Prurigo

@Prurigo 555-123-1234, 07777777777, 90210, 01/01/1901 - users are inventive in ramming garbage through validation. Better to not tic off the ones who genuinely do have some odd data by using overly restrictive validation and telling them they're wrong. – Shaunda

Answer 24

Here's one that works well in JavaScript. It's in a string because that's what the Dojo widget was expecting.

It matches a 10 digit North America NANP number with optional extension. Spaces, dashes and periods are accepted delimiters.

"^(\\(?\\d\\d\\d\\)?)( |-|\\.)?\\d\\d\\d( |-|\\.)?\\d{4,4}(( |-|\\.)?[ext\\.]+ ?\\d+)?$"

Atonal

Answer 25

You would probably be better off using a Masked Input for this. That way users can ONLY enter numbers and you can format however you see fit. I'm not sure if this is for a web application, but if it is there is a very click jQuery plugin that offers some options for doing this.

http://digitalbush.com/projects/masked-input-plugin/

They even go over how to mask phone number inputs in their tutorial.

Jibe

Answer 26

I found this to be something interesting. I have not tested it but it looks as if it would work

<?php
/*
string validate_telephone_number (string $number, array $formats)
*/

function validate_telephone_number($number, $formats)
{
$format = trim(ereg_replace("[0-9]", "#", $number));

return (in_array($format, $formats)) ? true : false;
}

/* Usage Examples */

// List of possible formats: You can add new formats or modify the existing ones

$formats = array('###-###-####', '####-###-###',
                 '(###) ###-###', '####-####-####',
                 '##-###-####-####', '####-####', '###-###-###',
                 '#####-###-###', '##########');

$number = '08008-555-555';

if(validate_telephone_number($number, $formats))
{
echo $number.' is a valid phone number.';
}

echo "<br />";

$number = '123-555-555';

if(validate_telephone_number($number, $formats))
{
echo $number.' is a valid phone number.';
}

echo "<br />";

$number = '1800-1234-5678';

if(validate_telephone_number($number, $formats))
{
echo $number.' is a valid phone number.';
}

echo "<br />";

$number = '(800) 555-123';

if(validate_telephone_number($number, $formats))
{
echo $number.' is a valid phone number.';
}

echo "<br />";

$number = '1234567890';

if(validate_telephone_number($number, $formats))
{
echo $number.' is a valid phone number.';
}
?>

Quanta

Your message seems to indicate that you didn't write this code. Would you mind citing a source, please? – Algesia

bitrepository.com/how-to-validate-a-telephone-number.html looks to be the source. – Lennyleno

Answer 27

I was struggling with the same issue, trying to make my application future proof, but these guys got me going in the right direction. I'm not actually checking the number itself to see if it works or not, I'm just trying to make sure that a series of numbers was entered that may or may not have an extension.

Worst case scenario if the user had to pull an unformatted number from the XML file, they would still just type the numbers into the phone's numberpad 012345678x5, no real reason to keep it pretty. That kind of RegEx would come out something like this for me:

\d+ ?\w{0,9} ?\d+

• 01234467 extension 123456
• 01234567x123456
• 01234567890

Legist

Answer 28

Find String regex = "^\\+(?:[0-9] ?){6,14}[0-9]$";

helpful for international numbers.

Woke

Answer 29

For anyone interested in doing something similar with Irish mobile phone numbers, here's a straightforward way of accomplishing it:

http://ilovenicii.com/?p=87

PHP

---

<?php
$pattern = "/^(083|086|085|086|087)\d{7}$/";
$phone = "087343266";

if (preg_match($pattern,$phone)) echo "Match";
else echo "Not match";

There is also a JQuery solution on that link.

EDIT:

jQuery solution:

    $(function(){
    //original field values
    var field_values = {
            //id        :  value
            'url'       : 'url',
            'yourname'  : 'yourname',
            'email'     : 'email',
            'phone'     : 'phone'
    };

        var url =$("input#url").val();
        var yourname =$("input#yourname").val();
        var email =$("input#email").val();
        var phone =$("input#phone").val();


    //inputfocus
    $('input#url').inputfocus({ value: field_values['url'] });
    $('input#yourname').inputfocus({ value: field_values['yourname'] });
    $('input#email').inputfocus({ value: field_values['email'] }); 
    $('input#phone').inputfocus({ value: field_values['phone'] });



    //reset progress bar
    $('#progress').css('width','0');
    $('#progress_text').html('0% Complete');

    //first_step
    $('form').submit(function(){ return false; });
    $('#submit_first').click(function(){
        //remove classes
        $('#first_step input').removeClass('error').removeClass('valid');

        //ckeck if inputs aren't empty
        var fields = $('#first_step input[type=text]');
        var error = 0;
        fields.each(function(){
            var value = $(this).val();
            if( value.length<12 || value==field_values[$(this).attr('id')] ) {
                $(this).addClass('error');
                $(this).effect("shake", { times:3 }, 50);

                error++;
            } else {
                $(this).addClass('valid');
            }
        });        

        if(!error) {
            if( $('#password').val() != $('#cpassword').val() ) {
                    $('#first_step input[type=password]').each(function(){
                        $(this).removeClass('valid').addClass('error');
                        $(this).effect("shake", { times:3 }, 50);
                    });

                    return false;
            } else {   
                //update progress bar
                $('#progress_text').html('33% Complete');
                $('#progress').css('width','113px');

                //slide steps
                $('#first_step').slideUp();
                $('#second_step').slideDown();     
            }               
        } else return false;
    });

    //second section
    $('#submit_second').click(function(){
        //remove classes
        $('#second_step input').removeClass('error').removeClass('valid');

        var emailPattern = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;  
        var fields = $('#second_step input[type=text]');
        var error = 0;
        fields.each(function(){
            var value = $(this).val();
            if( value.length<1 || value==field_values[$(this).attr('id')] || ( $(this).attr('id')=='email' && !emailPattern.test(value) ) ) {
                $(this).addClass('error');
                $(this).effect("shake", { times:3 }, 50);

                error++;
            } else {
                $(this).addClass('valid');
            }


        function validatePhone(phone) {
        var a = document.getElementById(phone).value;
        var filter = /^[0-9-+]+$/;
            if (filter.test(a)) {
                return true;
            }
            else {
                return false;
            }
        }

        $('#phone').blur(function(e) {
            if (validatePhone('txtPhone')) {
                $('#spnPhoneStatus').html('Valid');
                $('#spnPhoneStatus').css('color', 'green');
            }
            else {
                $('#spnPhoneStatus').html('Invalid');
            $('#spnPhoneStatus').css('color', 'red');
            }
        });

     });

        if(!error) {
                //update progress bar
                $('#progress_text').html('66% Complete');
                $('#progress').css('width','226px');

                //slide steps
                $('#second_step').slideUp();
                $('#fourth_step').slideDown();     
        } else return false;

    });


    $('#submit_second').click(function(){
        //update progress bar
        $('#progress_text').html('100% Complete');
        $('#progress').css('width','339px');

        //prepare the fourth step
        var fields = new Array(
            $('#url').val(),
            $('#yourname').val(),
            $('#email').val(),
            $('#phone').val()

        );
        var tr = $('#fourth_step tr');
        tr.each(function(){
            //alert( fields[$(this).index()] )
            $(this).children('td:nth-child(2)').html(fields[$(this).index()]);
        });

        //slide steps
        $('#third_step').slideUp();
        $('#fourth_step').slideDown();            
    });


    $('#submit_fourth').click(function(){

        url =$("input#url").val();
        yourname =$("input#yourname").val();
        email =$("input#email").val();
        phone =$("input#phone").val();

        //send information to server
        var dataString = 'url='+ url + '&yourname=' + yourname + '&email=' + email + '&phone=' + phone;  



        alert (dataString);//return false;  
            $.ajax({  
                type: "POST",  
                url: "http://clients.socialnetworkingsolutions.com/infobox/contact/",  
                data: "url="+url+"&yourname="+yourname+"&email="+email+'&phone=' + phone,
                cache: false,
                success: function(data) {  
                    console.log("form submitted");
                    alert("success");
                }
                });  
        return false;

   });


    //back button
    $('.back').click(function(){
        var container = $(this).parent('div'),
        previous  = container.prev();

        switch(previous.attr('id')) {
            case 'first_step' : $('#progress_text').html('0% Complete');
                  $('#progress').css('width','0px');
                       break;
            case 'second_step': $('#progress_text').html('33% Complete');
                  $('#progress').css('width','113px');
                       break;

            case 'third_step' : $('#progress_text').html('66% Complete');
                  $('#progress').css('width','226px');
                       break;

        default: break;
    }

    $(container).slideUp();
    $(previous).slideDown();
});


});

Source.

Crosier

Answer 30

    pattern="^[\d|\+|\(]+[\)|\d|\s|-]*[\d]$" 
    validateat="onsubmit"

Must end with a digit, can begin with ( or + or a digit, and may contain + - ( or )

Bacillary

Answer 31

My inclination is to agree that stripping non-digits and just accepting what's there is best. Maybe to ensure at least a couple digits are present, although that does prohibit something like an alphabetic phone number "ASK-JAKE" for example.

A couple simple perl expressions might be:

@f = /(\d+)/g;
tr/0-9//dc;

Use the first one to keep the digit groups together, which may give formatting clues. Use the second one to trivially toss all non-digits.

Is it a worry that there may need to be a pause and then more keys entered? Or something like 555-1212 (wait for the beep) 123?

Tenth

Answer 32

As there is no language tag with this post, I'm gonna give a regex solution used within python.

The expression itself:

1[\s./-]?\(?[\d]+\)?[\s./-]?[\d]+[-/.]?[\d]+\s?[\d]+

When used within python:

import re

phonelist ="1-234-567-8901,1-234-567-8901 1234,1-234-567-8901 1234,1 [phone],1.234.567.8901,1/234/567/8901,12345678901"

phonenumber = '\n'.join([phone for phone in re.findall(r'1[\s./-]?\(?[\d]+\)?[\s./-]?[\d]+[-/.]?[\d]+\s?[\d]+' ,phonelist)])
print(phonenumber)

Output:

1-234-567-8901
1-234-567-8901 1234
1-234-567-8901 1234
1 [phone]
1.234.567.8901
1/234/567/8901
12345678901

Recessive

Answer 33

It's near to impossible to handle all sorts of international phone numbers using simple regex.

You'd be better off using a service like numverify.com, they're offering a free JSON API for international phone number validation, plus you'll get some useful details on country, location, carrier and line type with every request.

Illsuited

Answer 34

Working example for Turkey, just change the

d{9}

according to your needs and start using it.

function validateMobile($phone)
{
    $pattern = "/^(05)\d{9}$/";
    if (!preg_match($pattern, $phone))
    {
        return false;
    }
    return true;
}

$phone = "0532486061";

if(!validateMobile($phone))
{
    echo 'Incorrect Mobile Number!';
}

$phone = "05324860614";
if(validateMobile($phone))
{
    echo 'Correct Mobile Number!';
}

Locker

Answer 35

I wouldn't recomend using a regex for this.

Like the top answer, strip all the ugliness from the phone number, so that you're left with a string of numeric characters, with an 'x', if extensions are provided.

In Python:

Note: BAD_AREA_CODES comes from a text file that you can grab from on the web.

BAD_AREA_CODES = open('badareacodes.txt', 'r').read().split('\n')

def is_valid_phone(phone_number, country_code='US'):
    """for now, only US codes are handled"""
    if country_code:
        country_code = country_code.upper()

    #drop everything except 0-9 and 'x'
    phone_number = filter(lambda n: n.isdigit() or n == 'x', phone_number)

    ext = None
    check_ext = phone_number.split('x')
    if len(check_ext) > 1:
        #there's an extension. Check for errors.
        if len(check_ext) > 2:
            return False
        phone_number, ext = check_ext

    #we only accept 10 digit phone numbers.
    if len(phone_number) == 11 and phone_number[0] == '1':
        #international code
        phone_number = phone_number[1:]
    if len(phone_number) != 10:
        return False

    #area_code: XXXxxxxxxx 
    #head:      xxxXXXxxxx
    #tail:      xxxxxxXXXX
    area_code = phone_number[ :3]
    head      = phone_number[3:6]
    tail      = phone_number[6: ]

    if area_code in BAD_AREA_CODES:
        return False
    if head[0] == '1':
        return False
    if head[1:] == '11':
        return False

    #any other ideas?
    return True

This covers quite a bit. It's not a regex, but it does map to other languages pretty easily.

Cowbell

Answer 36

As another post advises, it is best to use libphonenumber and/or possibly other well-maintained libraries for this, rather than a regular expression. I want to mention two other useful resources.

intl-tel-input

Aside from (1) google-libphonenumber, (2) International Telephone Input is a good frontend library (GitHub links). intl-tel-input also has a nice searchable drop-down feature with flags, and many useful functions - for instance allowing precise or imprecise validation (the latter being less susceptible to changed formatting rules), and for formatting the number.

Also, it makes sense to validate the number both front-end so as not to forward invalid numbers in vain, and back-end so as not to store invalid numbers.

PhoneValidator.JS

To that end, if you are using Node back-end, (3) PhoneValidator.JS is a wrapper of the two aforementioned libraries that lets you implement phone number validation with just a couple of lines front-end and back-end, and also includes a green-valid/red-invalid toggle of the field background - while retaining the nice design of intl-tel-input and the power of google-libphonenumber.

If you only want the backend part, you can of course use only that, still with just two lines of code, and possibly combine it with the React component that intl-tel-input provides here.

If you have very specific needs PhoneValidator.JS may not be for you, but otherwise it is a fast and easy way to get frontend and backend validation implemented. And of course, customizations can still be done by looking at the google-libphonenumber (link to Node version) and intl-tel-input documentation.

Front-end

const htmlIds = { formId: 'formId', inputFieldId: 'inputId' };

let phoneValidator = new PhoneValidatorFE(htmlIds); // an 'options' argument optional

The instantiation also adds the hidden fields countryCode and domesticPortion to the form. Before submitting the form or calling your API you may validate the number via:

if(phoneValidator.validNumber()) {

Back-end

The backend validation-method takes an object as an argument with the two same properties that were sent via hidden fields from the frontend:

let number = { countryCode: req.body.countryCode, domesticPortion: req.body.domesticPortion };

if(PhoneValidator.isPhoneNumber(number)) {

If valid, the number object now contains for instance:

{
  countryCode: '46',
  regionCode: 'SE',
  countryName: 'Sweden',
  domesticPortion: ’9 99 99 99’,
  full: {
    international: '[phone]’,
    domestic: '09-99 99 99’
  }
};

Barrage

Answer 37

I believe this is the one You'll need to detect phone numbers, you also should use a line of programming just to ensure a valid number.

((\+ ?)?(\(\d{1,5}\)[ \-.]?)?\d+([ \-.]?\d+)*)

The 1st capturing group is the number.

This will check

• + country code
• (555)
• multiple (- and space)

Once you get the number, to verify it's best to check their length (min 4 yes 4 digits exist, max 15) Python example:

def validate_number(number:str):
    n = sum([1 if c.isdigit()  else 0 for c in number ])
    
    return n >= 4 and n <= 15

JS example

function validate_number(number){
    n = 0
    for(i=0;i<number.length;i++){
        // check if the character is a number
        if(/^\d+$/.test(number.charAt(i))){
            n += 1
        }
    }
    return (n>=4 && n<=15)
}

Diacetylmorphine

Answer 38

I chose below regExp but when I copy and paste phone numbers it didn't work

/^(\+?\d{0,4})?[ -]?(\(?\d{3}\)?)[ -]?(\(?\d{3}\)?)[ -]?(\(?\d{4}\)?)?$/

The reason is there was a different dash symbol(this ‑ not -). So I modified regExp again by adding it too.

/^(\+?\d{0,4})?[ -‑]?(\(?\d{3}\)?)[ -‑]?(\(?\d{3}\)?)[ -‑]?(\(?\d{4}\)?)?$/

Storm

Answer 39

Although it's not regex, you can use the function validate_phone() from the Python library DataPrep to validate US phone numbers. Install it with pip install dataprep.

>>> from dataprep.clean import validate_phone
>>> df = pd.DataFrame({'phone': ['1-234-567-8901', '1-234-567-8901 x1234', 
         '1-234-567-8901 ext1234', '1 [phone]', '1.234.567.8901',
         '1/234/567/8901', 12345678901, '12345678', '123-456-78987']})
>>> validate_phone(df['phone'])
0     True
1     True
2     True
3     True
4     True
5     True
6     True
7    False
8    False
Name: phone, dtype: bool

Bluster

Answer 40

Java generates REGEX for valid phone numbers

Another alternative is to let Java generate a REGEX that macthes all variations of phone numbers read from a list. This means that the list called validPhoneNumbersFormat, seen below in code context, is deciding which phone number format is valid.

Note: This type of algorithm would work for any language handling regular expressions.

Code snippet that generates the REGEX:

Set<String> regexSet = uniqueValidPhoneNumbersFormats.stream()
        .map(s -> s.replaceAll("\\+", "\\\\+"))
        .map(s -> s.replaceAll("\\d", "\\\\d"))
        .map(s -> s.replaceAll("\\.", "\\\\."))
        .map(s -> s.replaceAll("([\\(\\)])", "\\\\$1"))
        .collect(Collectors.toSet());

String regex = String.join("|", regexSet);

Code snippet in context:

public class TestBench {

    public static void main(String[] args) {
        List<String> validPhoneNumbersFormat = Arrays.asList(
                "1-234-567-8901",
                "1-234-567-8901 x1234",
                "1-234-567-8901 ext1234",
                "1 [phone]",
                "1.234.567.8901",
                "1/234/567/8901",
                "12345678901",
                "[phone]",
                "[phone] ext. 123",
                "[phone] ext. 123",
                "1 [phone] ext. 123",
                "00 1 234-567-8901 ext. 123",
                "[phone]",
                "210-998-234-01234",
                "[phone]",
                "+210-(998)-(234)-(01234)",
                "([phone]",
                "90191919908",
                "555-8909",
                "001 6867684",
                "001 6867684x1",
                "1 [phone]",
                "1-234-567-8901 x1234",
                "1-234-567-8901 ext1234",
                "1-234 567.89/01 ext.1234",
                "1(234)5678901x1234",
                "(123)8575973",
                "(0055)(123)8575973"
        );

        Set<String> uniqueValidPhoneNumbersFormats = new LinkedHashSet<>(validPhoneNumbersFormat);

        List<String> invalidPhoneNumbers = Arrays.asList(
                "+210-99A-234-01234",       // FAIL
                "[phone]\"\"234",    // FAIL
                "[phone];4",        // FAIL
                "-210+998-234-01234",       // FAIL
                "+210-998)-(234-(01234"     // FAIL
        );
        List<String> invalidAndValidPhoneNumbers = new ArrayList<>();
        invalidAndValidPhoneNumbers.addAll(invalidPhoneNumbers);
        invalidAndValidPhoneNumbers.addAll(uniqueValidPhoneNumbersFormats);

        Set<String> regexSet = uniqueValidPhoneNumbersFormats.stream()
                .map(s -> s.replaceAll("\\+", "\\\\+"))
                .map(s -> s.replaceAll("\\d", "\\\\d"))
                .map(s -> s.replaceAll("\\.", "\\\\."))
                .map(s -> s.replaceAll("([\\(\\)])", "\\\\$1"))
                .collect(Collectors.toSet());

        String regex = String.join("|", regexSet);

        List<String> result = new ArrayList<>();
        Pattern pattern = Pattern.compile(regex);
        for (String phoneNumber : invalidAndValidPhoneNumbers) {
            Matcher matcher = pattern.matcher(phoneNumber);
            if(matcher.matches()) {
                result.add(matcher.group());
            }
        }

        // Output:
        if(uniqueValidPhoneNumbersFormats.size() == result.size()) {
            System.out.println("All valid numbers was matched!\n");
        }    
        result.forEach(System.out::println); 
    }

}

Output:

All valid numbers was matched!

1-234-567-8901
1-234-567-8901 x1234
1-234-567-8901 ext1234
...
...
...

Coetaneous

Answer 41

Try this (It is for Indian mobile number validation):

if (!phoneNumber.matches("^[6-9]\\d{9}$")) {
  return false;
} else {
  return true;
}

Excellency

Why not just return the output of matches? – Russel

Answer 42

Note It takes as an input a US mobile number in any format and optionally accepts a second parameter - set true if you want the output mobile number formatted to look pretty. If the number provided is not a mobile number, it simple returns false. If a mobile number IS detected, it returns the entire sanitized number instead of true.

    function isValidMobile(num,format) {
        if (!format) format=false
        var m1 = /^(\W|^)[(]{0,1}\d{3}[)]{0,1}[.]{0,1}[\s-]{0,1}\d{3}[\s-]{0,1}[\s.]{0,1}\d{4}(\W|$)/
        if(!m1.test(num)) {
           return false
        }
        num = num.replace(/ /g,'').replace(/\./g,'').replace(/-/g,'').replace(/\(/g,'').replace(/\)/g,'').replace(/\[/g,'').replace(/\]/g,'').replace(/\+/g,'').replace(/\~/g,'').replace(/\{/g,'').replace(/\*/g,'').replace(/\}/g,'')
        if ((num.length < 10) || (num.length > 11) || (num.substring(0,1)=='0') || (num.substring(1,1)=='0') || ((num.length==10)&&(num.substring(0,1)=='1'))||((num.length==11)&&(num.substring(0,1)!='1'))) return false;
        num = (num.length == 11) ? num : ('1' + num);   
        if ((num.length == 11) && (num.substring(0,1) == "1")) {
            if (format===true) {
               return '(' + num.substr(1,3) + ') ' + num.substr(4,3) + '-' + num.substr(7,4)
            } else {
               return num
            }
        } else {
            return false;
        }
    }

Wainscot

Answer 43

since there are so many options to write a phone number, one can just test that are enough digits in it, no matter how they are separated. i found 9 to 14 digits work for me:

^\D*(\d\D*){9,14}$

true:

• 123456789
• 1234567890123
• +123 (456) 78.90-98.76

false:

• 123
• (1234) 1234
• 9007199254740991
• 123 wont do what you tell me
• +123 (456) 78.90-98.76 #543 ext 210>2>5>3
• [phone] in the morning (987) 54-3210 after 18:00 and ask for Shirley

if you do want to support those last two examples - just remove the upper limit:

(\d\D*){9,}

(the ^$ are not needed if there's no upper limit)

Tranche

Answer 44

If at all possible, I would recommend to have four separate fields—Area Code, 3-digit prefix, 4 digit part, extension—so that the user can input each part of the address separately, and you can verify each piece individually. That way you can not only make verification much easier, you can store your phone numbers in a more consistent format in the database.

Illustrative

However, if you decide to go this route, keep in mind that this will not work outside the US. No way to enter a country extension, and e.g. Germany has variable-length area codes (anywhere from 2-4 digits, plus a leading zero if you're dialing from within Germany, which is left out if you have a country code before it). – Lamanna

Answer 45

Simple regex and other tricks works.

.*

but showing an Hint / Example / Placeholder / Tooltip for the input.

Then verifying on the frontend before submitting that the format is actually correct is a best experience out there.

This would simplify formats for an inexperienced user.

Poster

Answer 46

/\b(\d{3}[^\d]{0,2}\d{3}[^\d]{0,2}\d{4})\b/

Sheared