Getting Started with CNAM Caller ID

Twilio supports Caller ID name (CNAM) lookups in a number of ways. Continue reading for an overview of how CNAM works with Twilio, and common questions.

This guide covers the following information:

What is CNAM?

Caller ID Name (CNAM) is a service used in telephone networks to provide the name of the calling party. The name can be a business or person, represented as a string of text no longer than 15 characters. CNAM cannot start with a number - it should begin with a letter and can only contain letters, numbers, periods, commas and spaces.

Telephone carriers are responsible for populating one of several authoritative databases with subscriber data, known as CNAM repositories and collectively referred to as the Line Information Database (LIDB).

Where does CNAM lookup work?

Caller name Lookup is sourced by authoritative CNAM data, which is only supported by carriers in the United States. CNAM lookups for phone numbers from other countries are not supported.

How can I lookup CNAM with Twilio?

Twilio offers customers a number of ways to lookup US CNAM entries:

  • Manual phone number query: Twilio's Lookup API allows users to search for CNAM entries for phone numbers in the US. For full details, see Getting Started with the Twilio Lookup API.
  • Elastic SIP Trunking: Twilio Elastic SIP Trunking allows users to enable automatic CNAM lookups for incoming (SIP Origination) calls on each trunk independently. This feature can be set on the Trunk origination settings page in Console, or via the REST API.
  • Programmable Voice: Twilio Programmable Voice allows users to enable automatic CNAM lookups for incoming calls on each phone number independently. This feature can be set on the Phone number configuration page in Console, or via the REST API.

Each CNAM lookup, regardless of the method, costs $0.01.

How do I edit or remove a CNAM entry?

Notice: Friendly Name is not the same as CNAM. Editing the Friendly name will not edit the CNAM. *Friendly Names are used as personalized titles or identifiers for your phone numbers.

To edit or remove a CNAM entry for a US Twilio phone number, you can follow our guide to Brand Your Calls Using CNAM.

To edit or remove the CNAM entry for your non-Twilio numbers, please contact your carrier. Your carrier is the only authority for the CNAM value associated with your phone number. They can change the name or remove the name entirely. Each carrier has a different policy on whether or not they automatically opt their subscribers into CNAM.


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