Check for existing Email/Password accounts when using SSO


We have a recurring issue where users are signing up with an email/password login, and then later they will attempt to use the “Login with Microsoft” button.

This lets them create a user which ends up partially creating a user in our database.

Is there a way we can handle this in our auth0 login form to prevent signups and give them an “existing user” error?

Hi @s.murray,

Thanks for reaching out to the Auth0 Community!

I understand that you would like to prevent users from signing up with their Microsoft social account after they have created an email and password account using the same email address.

Unfortunately, I would like to clarify that the behavior you have observed is expected since these users belong to different database connections, namely, Username-Password-Authentication and windowslive.

Hence, you will see two copies of the user email address, one referring to the Username-Password-Authentication database and the other referring to the windowslive database.

In this case, I recommend considering the Account Linking option, which would link the user’s secondary account to their primary account. This is a great option to allow your users to use either method to log in but retain a single user profile for consistency.

Please let me know how this works for you!

Thank you.