Prevent Sign Up for an an Email that already exist

Hi @novo,

Welcome to the Auth0 Community!

I understand that you’re running into a problem where users are creating multiple profiles with the same email address when logging in with multiple identity providers.

It is possible to block the signup process when a user tries to sign up with an email address that’s already associated with a profile in your tenant, but that would not be the solution I’d suggest. One reason is because it would lead to a confusing experience for the user and you wouldn’t be able to provide them with feedback on why they’re not able to sign up without revealing that there’s already a profile with that email address, which is a security concern.

In my opinion account linking is the way to go here, in part because it provides your users the convenience of authenticating via multiple identity providers. I have an account linking rule that meets the qualifications you’re describing and if you send me a DM I’d be happy to reply with the code for that rule.

I hope this helps!

Thanks,
Matt

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