Make mobile numbers unique - prevent users with same mobile to sign up again

Help
1

Hi all,

I would like to make users unique based on their mobile number. This should prevent creating fake accounts in my application.

Can I do this within Auth0 Hooks / Rules?

2

Technically if you only allow users to login through a passwordless SMS connection (Passwordless Authentication with SMS) you have achieved your requirement implicitly. If you need to allow other means of login, you could still technically use this connection and account linking to ensure each user has a verified mobile number.

3

I need both. E-Mail and Mobile. How does this account linking work?

Can this give the user an error if he tries to sign up a second time with same mobile but different email?

4

There’s reference information on account linking at (https://auth0.com/docs/link-accounts). Although it would require custom logic on your side to ensure each account has an associated SMS passwordless account it is technically feasible for you to perform a custom integration where a user after signing up with email are forced to also a mobile number (SMS account).

5

I ended up implementing my own solution. That hast the benefit that I can let the user login with his email and later ask him for his mobile number.

I might link it to auth0 later.

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6

Thanks for letting us know!