Sign in with Apple - Hide email

Question

On 'Sign in with Apple' If the user opted for “Hide my Email”, he will be registered with a private email id. Again if the same user tries to Register with the original email address (with any social media account or with original email id), he will be treated as a different user?

How is it possible to make sure we have a unique user in the database after registration?

Answer 1

As per apple doc: link (https://support.apple.com/en-in/HT210425)

If you choose to hide your email when you create an account with an app or website using Sign in with Apple, a unique, random email address is created so your personal email can stay private.

To answer your question:

If user sign-in with actual email id from another platform/social login then this will be a new user for you.

Answer 2

Don't use the email address as an unique identifier, you can use the "sub" parameter returned in the identity Token JWT, the value of this parameter is the same for the same Apple ID user and is unique, across all apps that belongs to your Apple developer account / organization.