Issue
Organizations may need to restrict which Twilio phone numbers or verified Caller IDs are visible or selectable by users in their applications or workflows. This is often required to prevent accidental use of sensitive, reserved, or integration-specific numbers.
Product
Twilio Flex
Environment
Twilio Console
Cause
By default, Twilio returns all verified Caller IDs and Twilio phone numbers associated with an account. There is no built-in feature in the Twilio Console or APIs to selectively hide or filter specific numbers for all users.
Resolution
There are two main approaches to control Caller ID visibility:
1. Application-Level Filtering (Recommended for Custom Apps)
- When building a custom application or plugin, retrieve the list of Caller IDs using the OutgoingCallerIds API or IncomingPhoneNumbers API.
- Implement filtering logic in your application to exclude numbers that should not be shown to end users. This can be based on friendly name, number pattern, or metadata maintained by your organization.
- Only display eligible numbers to users in your application's UI.
2. Account Segregation (For Console Users)
- Use Twilio Subaccounts to separate phone numbers by purpose or user group.
- Assign users to subaccounts according to the numbers they should access.
- Use Role-Based Access Control (RBAC) to restrict user access to only the appropriate subaccount.
Additional Information
- Maintain clear documentation or metadata to identify which numbers should be filtered or hidden.
- Regularly review and update filtering logic as your number inventory or business requirements change.
- For integrations, coordinate with third-party vendors to ensure number assignments are clearly tracked.
Below you will find references to useful documents: