Hong Kong phone number +85250260414 flagged as invalid — why?

Hi Auth0 community,

I’m running into an issue where a Hong Kong phone number is being flagged as invalid, and I’m trying to understand the root cause.

The number: +85250260414

The validation regex: /^\+[0-9]{1,15}$/

When I test this number against the regex, it passes:

  • Starts with + :white_check_mark:
  • Followed by 11 digits (85250260414) :white_check_mark:
  • Within the 1–15 digit range :white_check_mark:
  • No spaces or special characters :white_check_mark:
    However, the number is still being flagged as invalid somewhere in the Auth0 flow.

It is working if I use 8525"1"260414

Any insight would be appreciated. Thanks!

Hi @louis.lui.ext

When do you receive this specific error?

When going through an MFA enrollment process, I was able to use a HK phone number as expected without any issues.

If you are trying to add a phone number either through the Management API or via the Dashboard, if the phone number is not an attribute assigned to the connection OR if you are not using a passwordless SMS connection, it will through the respective error.

Could you also double check if the phone number you are trying to use is indeed a valid HK number which does not violate any other rules?(such as the region codes

Let me know if you have any other questions!

Kind Regards,
Nik