Validates a phone number and checks if it appears in any Do Not Call registries. Returns DNC status and source information if found.
Note: Phone numbers should follow the E.164 format for best results - i.e. +<country-code> <phone-number>.
For countries like the USA or Canada there isn’t much difference between dialing locally or internationally, i.e. +1 (678) 123-4567 versus (678) 123-4567. For countries like the United Kingdom however, there’s a bigger difference between local and international format, i.e. 01000822380 would become +44 1000822380 - notice we drop the leading 0. We will still try our best to match your number to our database, but know that this has limitations.
Rate Limiting: This endpoint counts against your monthly request limit.
API key authentication. Provide your API key in the Authorization header:
Authorization: Bearer YOUR_API_KEY
You can also omit the "Bearer" prefix:
Authorization: YOUR_API_KEY
Phone number to check (e.164 format recommended, e.g., +1234567890)
Successfully checked phone number
Whether the phone number is on a Do Not Call list
true
RFC3339 timestamp of when the check was performed
"2025-12-16T14:32:10.123456789Z"
The source of the DNC listing (null if not on any list)
"National Do Not Call Registry"