Use Custom Database with existing Username-Password-Authentication users


I want to enable a Custom Database on an existing Username-Password-Authentication database. What happens to the users who already have usernames and passwords in Auth0? Will they still be able to sign in after toggling the Custom Database?

For now I wanted to test it without migrating users across, will Auth0 still check the local database if Import Users to Auth0 is not checked?

Hi @jeremy3

You cannot change a DB to a custom DB after it has users.

What is your use case for this? For lazy migration? If so, you have to set up the lazy migration first, before adding users


Hi @john.gateley,

Thanks for getting back to me. My use case is migrating two groups of existing users into one database in Auth0. I currently have users in a third party system, and users already in Auth0. But because I can only have one database connection per application, I can’t create a second database for the custom DB.

It seems like I can’t migrate users across while allowing both groups to continue to log into the app.


Hi @jeremy3

Create a new DB connection, set it up to lazy migrate from your 3rd party system, and then bulk migrate the users from the Auth0 DB connection into it. Then change your application to use that new connection.


Ah, bulk migrate into the second DB! Good suggestion, thank you. I’ll try this.