Bulk User Import and Lazy Migration

Last Updated: Sep 10, 2025

Overview

When users are bulk imported from a legacy database connection, a number of DUPLICATED_USERS errors appear, even when sending the user_id and the "upsert" value as true.

Applies To

Bulk Import
Duplicate User Error
Partial User Record

Cause

Using both types of migration, lazy migration and bulk user imports, can result in this error when trying to import users that logged in before turning import mode on. This creates a partial user record in Auth0 that causes the duplicated user error.

Solution

The only workaround currently is to delete the users with the users endpoint in order to remove the incomplete record from Auth0.