How do I include extensions in the tel: URI?

Question

I currently have a webpage serving up phone numbers, some of these phone numbers have extensions so I have written the HTML like this:

<a href="tel:[phone];ext=88">[phone]</a> / <a href="tel:[phone];ext=99">[phone]</a

When I hit this page in my Android browser and tap one of the phone numbers, it loads up in my phone dialer (UK Samsung Galaxy s2 stock) as:

[phone];ext=88

which I don't think is correct. Surely it should omit the ;ext= word.

Have I misread the RFC for implementing tel?

Morman

Just because you’ve read the spec correctly doesn’t mean the phone dialer has implemented it correctly. ☹ – Englishman

Has anyone tested all of these answers on iPhone and Android? I would guess 90%+ click to call calls would come from fairly recent iOS and Android devices. Sure you might have 50%+ desktop visitors on your site, but those people are probably dialing by hand. – Prelatism

Answer 1

Seems the proper way to do it is use a comma:

<a href="tel:[phone],88">[phone] ext.88</a>

Just tested with iPhone and Android OS 2.1. Using ;ext=88 converts the ext bit into a number that is dialed with the extension (so it dials something like 35888 instead of 88).

Photoluminescence

This answer is definitely wrong as you removed the "+" completely. I don't understand why so many users upvoted this, see my answer below for the correct version. – Callisto

Answer 2

Comment for How do I include extensions in the tel: URI?

As of June 2021 the RFC3966 ;ext= syntax still isn't implemented by Android, and it's inelegantly implemented by iOS.

Using ;ext=123 as an example:

• Android: after the call connects a modal window appears asking Send the following tones? 396123 with No and Yes buttons. "Send the following tones?" is a precise technical description of what will happen if the user taps Yes, but it is probably not the best wording for the average user.
• Android converts ;ext=123 into 396123 because it treats the letters the same way as if you were dialing something like 1-800-FLOWERS, and this is a broken implementation of the syntax.
• iOS provides an option to the left of the Disconnect button that says Dial “ext=…”. When you tap on this "button" it will dial the extension number. This is inelegant and has bad usability because the "button" doesn't look like a button — it's just plain text — and because you can't see the extension number.
• In addition, when you first tap on a phone link in iOS it presents a button at the bottom of the screen which partially rewrites the phone number into a local format, but which also preserves most of the ;ext= syntax, e.g. Call [phone];ext123. This is also inelegant, and it's ugly besides.

If you instead use just a ; which is supposed to mean "wait," as in "wait until the auto attendant message ends and then automatically dial the extension":

• iOS: tapping the link displays a button stating Call [phone];123 which is slightly less ugly than the button described above.
• iOs provides the same extension-dialing "button" described above except the extension number is visible, e.g. Dial “123”. It still has the other usability problems.
• iOS does not automatically dial the extension after the message ends.
• Android: after the call connects a modal window appears asking Send the following tones? 123 with No and Yes buttons.
• Android does not automatically dial the extension after the message ends.

So for now, as of June 2021 it seems that the only way to include extensions in tel: links that will actually work is to use either ; for "wait" or , for "pause":

• <a href="tel:[phone];123">555-555-5555 ext. 123</a> — this will provide a UI component which the user can invoke to dial the extension. The usability of the UI component depends on the OS; neither are great, but Android's is arguably better.
• <a href="tel:[phone],123">555-555-5555 ext. 123</a> — this will automatically dial the extension a couple seconds after the call connects. Note: This mechanism will not work with voicemail systems that don't accept user input until the auto attendant message ends.

Kris

Sounds like this would be worth reporting a issuetracker.google.com/issues/… for. Can anyone verify that the issues stated in stackoverflow.com/revisions/67810744/3 remain reproducible in 2024? – Minardi

Answer 3

According to the documentation, you can add what you want like so 12345678;ext=123

See RFC 3966

Andradite

Why was this downvoted? It's from 2012 but is a valid source. – Gromwell

W3.Org relates above mentioned RFC 3966 as the most broadly supported scheme w3.org/TR/mwabp/#bp-interaction-uri-schemes – Gromwell

Answer 4

In all the examples I saw, the value of ext is contained in the full number. So try including 88 in the href value:

<a href="tel:[phone];ext=88">[phone]</a>

Poulter

It still tells you which part of the whole number corresponds to the extension. Don't know how would browsers handle that, though. I'd have to check the RFC. – Poulter

Answer 5

For those still wondering about this problem: I've found it best to use this format:

<a href="tel:[phone];22">

Gratifying

I love how every answer to this question is completely different lol – Phenol

Answer 6

Standards at thenewcode from 3 months ago suggest using a microdata pause.

<a href="tel:[phone]p22">

Related: Different standards persist across different external platforms and may change the processing of URIs. Click to call features on Google Developers docs do not specify

Example: Office's Skype uses x to represent extension within skype.

Gromwell

apple dev also does not appear to have a standard for URI extension – Gromwell

Nice addition @systemaddict. Unfortunately, 'p' auto-converted to a number on Android v7 on my Samsung in US. – Shammer

Answer 7

I don't get the answers to this question - I think the're wrong. The correct link would look like this:

<a href="tel:[phone],88">[phone] ext. 88</a>

Callisto

it is the only format that works on both Android and iOS – Apocarpous

Answer 8

I feel like this is kind of a cop-out answer, but if this is not implemented consistently across devices yet, probably best to just not include the extension and let people dial it by hand:

<a href="tel:[phone]">[phone] ext. 88</a>

or

<a href="tel:[phone]">[phone]</a> ext. 88

Better to make the user do more work than to send 1/2 your users to the wrong extension.

Prelatism