This section in Firebase documentation shows how to link a single account to multiple auth providers. For example, a user who signed in with a password can link a Google account and sign in with either method in the future. But it doesn't say anything about linking two emails or two phone numbers to the same account. So, I was asking if it was possible to link multiple credentials of the same auth providers to a single account.

A similar question has been asked previously here, but it has no answers!

CodePudding user response：

Currently, there is no way you can merge two Firebase accounts created with two different phone numbers into a single one.

On the other hand, when it comes to authentication with email and password, by default, you can use one account per email address. This is done to prevent users from creating multiple accounts using the same email address with different authentication providers. However, this can be changed in the Firebase console, in the "Sign-in method" tab, inside the Authentication section.