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Multiple usernames with the same email in one connection



I have a legacy system which requires unique username but allows multiple users to have the same email.

When I tried to create two accounts according to this scheme, Auth0 showed me an error with the note that second account already exists(despite it had a unique username).

Is it possible to achieve a legacy system behaviour(maybe with the help of rules) with the Auth0?

(My legacy app is written in Python and uses Postgres)

Update: I was able to import such users via Import/Export tool. However, I can log in only into one account(other are inaccessible).


Auth0 Database Connections currently only support unique email addresses, hence why you cannot register multiple users with the same email address. The only way this is achievable is if the users with the same email address are split into different database connections. Can you describe why you’d require multiple users with the same email address?


It is possible to have same email addresses for multiple users mostly because of a historical(i.e. legacy) reasons. Actually, this is a requirement from one of the subprojects that we use(called CKAN). I am not aware why its chosen this behaviour, but maybe I can additionally check with them.

Thanks for your answer!


The only way to have the same email for multiple users it to have each user in a different database connection. E.g.

User 1 ( -> Connection 1

User 2 ( -> Connection 2


I’ve a question

I have two different connections like described below. Each connection has a user with email My client uses both connections and for example a google login connection. Both users area created under users and share the same email but having a different connection.

Now when i log in via google for example with how does Auth0 know which user it has to take because i have two users with identical email ?


I have one client and I created multiple connections for it to be able to have multiple username with the same email.
When I try to login using the newly created user, I get a wrong Username/Pwd error.
Any idea what I might be doing wrong?