Should TTY phone numbers be hyperlinks like normal numbers?

Question

Most website developers know how to use tel: syntax for phone number references to provide easy mobile dialing:

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

Do the same for TTY numbers ? Are there other or additional methods that should be used to ensure accessibility?

Answer 1

Yes, that's enough (maybe add some description that will say its TTY number). A deaf person can click a link in the same way as a deaf person, if you are not using sounds on your website, that’s enough.

TTY setup on the phone: https://support.apple.com/en-ca/HT207033

If you plan to make your site accessible to blind people, then I suggest you read https://webaim.org/techniques/hypertext/

Answer 2

In accordance with RFC3966 :

The terminal address can support any electronic communications service (ECS), including voice, data and fax. The URI may refer to resources identified by the phone number, including, but not limited to, initiators or targets of the phone call.

For accessibility, you must indicate in the link content that the telephone line is TTY.

 <a href="tel:[phone]">TTY: [phone]</a>