Account Linking Extension Not Linking Two Accounts with Same Email
Feb 20, 2026
Overview
This article addresses an issue that arises when using the Account Linking Extension to link two accounts that have the same email.
Applies To
- Identity Provider (IdP)
- Account Linking Extension
- Case Sensitivity
Cause
Currently, the extension (both in the rules and in the backend) searches for identities with the same email address using the GET /api/v2/users-by-email endpoint.
While this endpoint is efficient, the search it performs is case-sensitive. This can be a problem for some enterprise identity providers that provide the email address in a capitalized form (For example, John.Doe@domain.com instead of john.doe@domain.com).
Solution
This is currently a limitation of the extension, and there is a backlog item to address this issue. Please contact Auth0 Support for an update.
