# unable_to_link_account (/docs/reference/errors/unable_to_link_account)

The account could not be linked.



## What is it? [#what-is-it]

This error occurs only during an OAuth flow when attempting to link the provider account to the
currently authenticated user. Better Auth blocks the operation if either:

1. The database operation to create/update the linked account fails.
2. The provider is not considered trusted for linking based on your auth configuration
   (`account.accountLinking.trustedProviders`).

## Common Causes [#common-causes]

* The provider is not listed in `account.accountLinking.trustedProviders`.
* Configuration differs across environments (dev/staging/prod), so the provider appears untrusted in one environment.
* Database write failed due to unique constraint, foreign key violation, or transaction/connection issues.
* A race condition linking the same provider concurrently caused a conflict.
* Pending migrations or a mismatched schema between services caused the write to fail.

## How to resolve [#how-to-resolve]

### Allow linking for the intended provider [#allow-linking-for-the-intended-provider]

* Add the provider id (e.g., `github`, `google`) to `account.accountLinking.trustedProviders` in your auth config.
* Verify you are using the correct provider id/slug that your integration expects.

### Fix database reliability and constraints [#fix-database-reliability-and-constraints]

* Run pending migrations and ensure the schema matches the current Better Auth version.
* Investigate DB errors (deadlocks, timeouts, connection pool limits) and retry if appropriate.

### Verify environment configuration [#verify-environment-configuration]

* Ensure the same auth config is deployed to all environments and that environment variables are loaded as expected.
* Double-check that the runtime sees the intended `trustedProviders` list.