v2
latestOpenAPI 3.1.02026-08-075421692.0 MBSMS
Look up carrier + line type
Carrier name and line type (mobile / landline / voip / toll-free) for a number, plus smsReachable (landlines can't receive SMS). Use it to validate recipients before sending. Each lookup is billed by the carrier-data provider, so call it explicitly (e.g. pre-validating an opt-in list), not on every send.
get/v1/sms/lookup
Query parameters
numberstring required
Number to look up (E.164; formatting is normalized).
Response
Lookup result. An unknown/invalid number returns lineType unknown with smsReachable false rather than an error.