Trust & Security

CNAM (Caller-ID Name)

CNAM is the human-readable name displayed alongside an inbound caller-ID. It is stored in distributed databases (LIDB) operated by US carriers and is queried at call-setup time, not during the SIP signaling.

How CNAM lookup works

1. An inbound call arrives at the terminating carrier with the calling number.
2. The carrier queries its CNAM provider (Neustar, BellSouth, Equifax, etc.) for the name registered against that number.
3. The result is inserted into the SIP From display name and shown on the recipient's phone.

CNAM lookup costs the terminating carrier ~$0.0025-$0.005 per dip. There is also a CNAM storage service for owners to register their preferred name.

Why CNAM matters

A registered, recognizable CNAM (e.g. 'ACME CORP') dramatically improves answer rates vs an unknown number. It is also a key signal for spam scoring — a number with mismatched CNAM data ('JOHN SMITH' on a number registered to 'ACME CORP') will be flagged.

CNAM exists primarily in NANP (US/Canada). EU/UK/APAC use other display-name mechanisms or just the E.164 number.

DIDHub CNAM

For US/Canada DIDs, set CNAM via dashboard → Number → CNAM. Propagation: 24-72h to all major LIDB databases.

Related terms