Invalid Phone number while enrolling for MFA

Hi team,

We have a customer who’s based out of China, and trying to enroll for MFA. They are getting the invalid-phone prompt message shown on the screen while trying to enter their phone number. They claim that the number is valid and is in operation. We are using Twilio as a message provider and there’s no logs associated with this call in Twilio as Auth0 throws the error directly saying “Seems that your phone number is not valid. Please check and retry.”

Need help on how to fix this particular issue. Other customers from China are able to add their phone number for MFA so doesn’t look like a country-specific issue. Is there any way we can debug this issue?


Hi @sulav,

Welcome to the Auth0 Community!

Hm, it will be difficult to debug without more info. Could you give an example of the number format? You can omit the actual numbers, but please provide a format (i.e. +1xxxxxxxxxx)

The format is +861891XXXXXXX. The total number length is 11 excluding country code (+86). I hope this helps.

Thank you! Also, are you using the Auth0 delivery provider, or another provider?

We have set up Twilio as a delivery provider from within the Auth0 (from Security → Multi-factor Auth → Phone Message → set Twilio as a message delivery).

1 Like

Great, thanks for the additional info.

I’m trying to narrow down whether or not it is the provider who is rejecting the number, or Auth0.

Are there any more details on the error that is being thrown? I can’t find a reference to that error code. Is it possible it is missing something in the message?

Hi Dan, like I said, the request never reached Twilio. The verification is being done from Auth0 and the error message being displayed is same as the invalid-phone prompt message that is listed here in this link : Customize New Universal Login Text Prompts

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.