Phone Number Inspector & Technical Validator
Analyze numbering-plan compliance, classify line types (mobile, landline, VoIP, toll-free), resolve country and carrier attribution, and convert raw phone numbers into standardized formats.
+1 800 555 0199
US •Technical Classification & Telephony Parameters
ITU-T E.164 SpecificationTechnical Distinction: Format Validity vs. Active Subscriber Assignment
Format and numbering-plan validity confirms the phone number strictly conforms to national telecom regulator specifications. It does not guarantee that the line is currently active, assigned to a subscriber, or reachable without real-time carrier signaling. Line-type classification and carrier attribution are derived from authorized national destination code prefixes and regulatory allocations. Carrier porting (LNP) and active subscriber connection require live network signaling.
Related Developer Testing & Verification Workflows
Frequently Asked Questions
What is the difference between an E.164 valid number and an active line?
An E.164 valid number conforms to the international standard for country code, area prefix, and digit count. However, formatting alone does not guarantee the line is currently connected to a cellular tower or assigned to an active subscriber.
How does SMSRiver determine line types like VoIP vs Mobile?
Line types are determined using official national prefix allocation records (such as FCC/NANPA in the US and BNetzA in Germany). Cellular blocks and known VoIP allocations are mapped to classify the line.
Can I integrate phone number lookups into my API or CI pipeline?
Yes. SMSRiver provides a dedicated REST endpoint at /api/v1/lookup/ and batch processing at /api/v1/lookup/batch/.