The end-of-life date for the service allowing the creation of more than one custom phone or custom email provider action was December 16, 2025. As a result, after that date, Auth0 starts enforcing a limit of one action per custom provider.

The process to remove access to the deprecated behavior has the following phases:

• January 19, 2026 - Remove access for tenants tagged as development or staging tenants. The transition occurs according to the tenant's environment tag when changes roll out for each environment. Therefore, changing a development tenant to production after the rollout phase is complete will not reinstate the deprecated behavior.
• March 2, 2026 - Remove access for outstanding tenants, including production tenants.

The dates above mark the day the rollout for a particular phase starts; each phase may take several weeks to complete, so different tenants in the same phase may not observe the change simultaneously.

Once the deprecated behavior is unavailable in a given tenant, attempts to create actions for these triggers will fail, with the following error responses, if an action for the respective trigger already exists.

Custom phone provider error response:

{
  "statusCode": 403,
  "error": "Forbidden",
  "message": "custom-phone-provider can only have one supported Action",
  "errorCode": "actions_cardinality_custom_phone_provider_not_allowed"
}

Custom email provider error response:

{
  "statusCode": 403,
  "error": "Forbidden",
  "message": "custom-email-provider can only have one supported Action",
  "errorCode": "actions_cardinality_custom_email_provider_not_allowed"
}

Systems that perform programmatic tenant management, particularly automated deployment systems utilizing tooling such as the Auth0 Deploy CLI or the Auth0 Terraform Provider, may encounter the above errors when targeting tenants that were previously configured manually or through other tools.

• Custom Phone Provider Action
• Custom Email Provider Action
• End of Life (EOL)

The service introduced a single-action limit for custom phone and email providers as part of a calendar year 2025 scheduled change. Since the introduction of these features, the Auth0 Dashboard has utilized the concept of a single action for each of these specific action triggers. Imposing a maximum limit on programmatically created actions for these triggers prevents misconfigurations that arise from differing interpretations across the Dashboard, Management API, and deploy tools.

On June 16, 2025, Auth0 announced the deprecation of the previous service behavior. The information provided in the original announcement is available in the respective Dashboard and Support Center notification.

If a tenant has historically created multiple actions for the same custom provider (email or phone) trigger, delete the non-required and non-bound excess actions to reduce potential confusion.

Additionally, ensure that systems performing programmatic tenant management do not attempt to create more than a single action for the same custom provider trigger. Using the Auth0 Terraform Provider requires either removing any pre-existing custom providers before transitioning to Terraform-based management or adequately initializing Terraform so that it correctly updates a pre-existing provider action instead of attempting to create additional provider actions.