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Getting Started with CNAM Caller ID

Twilio supports Caller ID name (CNAM) changes and lookups for Twilio owned United States (US) numbers.

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CNAM stands for Caller ID Name. CNAM is a feature in the United States public telephone network that identifies an incoming caller by a personal or business name associated with the calling party.

  • If no Caller Name (CNAM) is set for the number, the City and State of the number is the default display along with phone number.

The CNAM of a number can be represented as a string of text no longer than 15 characters and presented in uppercase letters as an industry standard.

  • Cannot start with a number, it should begin with a letter.
  • Can only contain letters, numbers, periods, commas and spaces.
  • Must be a unique name or value, cannot be a generic value such as a City/State.

When the recipient receives a call, their carrier is responsible for displaying the assigned caller name by querying the appropriate databases containing CNAM data entries. These databases are known as CNAM repositories and collectively referred to as the Line Information Database (LIDB).

  • This will only happen when the recipient has CNAM services enabled on their phone plan. Some carriers may charge a fee for this service on inbound calls.

How do I check my number's CNAM?

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

  • Twilio Console's Lookup tool: No coding required. Check the ‘caller name’ box
  • API phone number query: Twilio's Lookup API allows users to search for CNAM entries for phone numbers in the US.
  • 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 update the Caller ID Name (CNAM) on my numbers?

Note:  If the number is not owned by Twilio please work with the owning carrier for any CNAM change needs. Twilio support cannot assist in changing CNAM for numbers Twilio does not own.

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.

Twilio has now made it easy to add, change, or delete entries through the use of Trust Hub onboarding, which can be done via Console (no coding required) or API.

  1. Trust Hub Business Profile via Console (No Coding): CNAM Onboarding in the Twilio Console
  2. REST API: CNAM Onboarding with the Trust Hub REST API

Note: At this time CNAM changes for Toll-Free numbers is not supported via Trust Hub API or Console. To update the CNAM of a Toll-Free number please contact support.

What is the difference between carriers and CNAM Databases (LIBD)?

The line information database (LIDB) is independently operated by local and other private telephone companies. LIDB is a collection of commercial databases used in the United States by telephone companies to store and retrieve Caller Names (CNAM) data used for caller ID services.

In the US, Carriers may subscribe to one or more of the CNAM databases and perform lookups, also known as ‘dips’, in order to associate the caller name for a given number. The recipient’s carrier has the responsibility to perform the CNAM lookup, and pass its values on to the recipient's phone.

Do all carriers support CNAM?

Most US carriers do support CNAM. If you have a customer reporting that a number is not displaying correctly see section: Why is my caller ID name (CNAM) displaying incorrectly?

Is there a fee or added charge related to CNAM?

Updating a CNAM on a Number

Twilio does not charge a fee for adding CNAM to or removing CNAM from Twilio numbers.

Checking the CNAM on a Number

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

Displaying CNAM to the Recipient of a Call

Mobile users in the US may need to subscribe with their carrier for CNAM to be displayed on their handset phones. Recipients can enable the CNAM feature on their phones by subscribing/opting in with their receiving carriers. Carriers may charge a fee for this feature.

Notice: If the call recipient has opted out of this service no CNAM will be displayed when that recipient receives a call from your number.

Why is my caller ID name (CNAM) displaying incorrectly?

Incorrect Caller Name information can be displayed under several circumstances.
Most commonly, US Carriers require the subscriber to opt-in.

  • It is likely that the recipient does not have the CNAM feature enabled on their phone and needs to contact their carrier to get CNAM feature enabled.

A specific carriers may have outdated CNAM information.

  • For the CNAM to be displayed accurately, the recipient’s carrier must query the CNAM databases (LIDB) and update their records.
  • If a carrier has not recently performed a query it may cause the recipient to see outdated CNAM information for the number.

How can Twilio help correct CNAM displays?

If the Lookup tool is displaying inaccurate CNAM information, please contact support, with the number(s) in question along with the correct CNAM to display. We can then verify that the CNAM database is updated correctly on our end.

If the CNAM database was updated correctly on Twilio’s end, the receiving party would then need to contact their carrier to ensure those records are also up-to-date, as well as being opted-in to display CNAM on their handsets.

Twilio provides support to our customers as well as self service resources to make CNAM changes. Ultimately, CNAM display is reliant upon the terminating carrier. Twilio makes every effort to update and correct a number's CNAM value, however, not all carriers may subscribe to the multiple CNAM databases available. We can only ensure that the Twilio CNAM databases are updated with the correct CNAM information for carriers to dip/source from. We cannot take responsibility for how a carrier or database provider manages their repositories, nor force them to update their records.

Nevertheless, as a best-effort service, Twilio will confirm and verify that a number’s CNAM has been correctly set and pass that value to the terminating carrier.

Does caller ID lookup (CNAM) work for all Twilio phone numbers?

At this time, only Twilio phone numbers from the United States fully support Caller ID (CNAM) lookups.

  • CNAM lookups for International phone numbers and other countries are not supported at this time.
  • Twilio does not support CNAM  for Canada, therefore, Twilio can not guarantee CNAM updates will display properly for Canada numbers at this time.

Why are my calls displaying a SCAM/SPAM label?

Consumers can easily submit spam or fraud reports against a number anytime for any reason.

Customers who conduct legitimate voice business may notice that their outbound calls are getting marked with nuisance call labels, such as ‘Scam Likely’, 'Spam', ‘Fraud Risk’, 'Robo Call', etc. This can be frustrating, and could result in outbound calls going unanswered, getting blocked, and CNAM being overwritten with a nuisance label.

To remove the nuisance label masking your CNAM you will need to register your numbers and apply key practices to ensure positive caller reputation. See this helpful guide on Outbound calls blocked or labeled as spam or scam likely.

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