From phone number is not valid SMS capable inbound phone number

Question

I am trying to use my Auth0 custom UI in android to login with phone number using AuthenticationAPIClient. I get this error when I call authAPIClient.passwordlessWithSMS:

The From phone number [phone] is not a valid, SMS-capable inbound phone number or short code for your account. (Code: 21606)

Looks like this is a Twilio error, I have checked in twilio console this UK number has voice and sms enabled, and I got this number as part of trial.

How can I get past this error?

Answer 1

Twilio developer evangelist here.

UK landline numbers, such as the one you have, cannot receive messages from international numbers. If you want to use a UK number, then I recommend getting a UK mobile number. They can send and receive SMS internationally, but cannot make voice calls (which shouldn't be a problem if you are using it for SMS login).

If this is a trial, then the number can also only send to numbers that you have verified in your account.

Does that help at all?