Phone validation and compliance
What is a phone line type?
Also called: phone number type, mobile vs landline
Line type is the kind of service behind a phone number: mobile, landline, VoIP or toll-free. It decides whether a number can receive SMS and which calling and texting rules apply. It can sometimes be read from the number itself, but often needs a live carrier lookup.
In many countries mobile numbers have their own prefixes, so the numbering plan gives the type. In the US and Canada it does not: mobile and landline numbers share area codes and exchanges, and numbers can be ported between landline, mobile and VoIP carriers. There, only carrier data can tell them apart.
Line type matters for SMS, because texts to most landlines fail, and for US compliance, because the TCPA treats calls and texts to mobile numbers more strictly.
Line type is about the service, not the person. A mobile number can be valid and still be unused or reassigned.
Example
+447 is mobile from the numbering plan alone. For a US number such as +14155550123 the numbering plan can only say mobile_or_landline; a carrier lookup is needed.How SimpleVerifier handles it
Every plan returns phone_type from the numbering plan. The Email + Phone plan adds a live carrier lookup through Telnyx (5,000 a month) that returns the real line type: mobile, landline, VoIP or toll-free.
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Sources
By SimpleVerifier Team · Last reviewed 2026-10-13 · All 50 glossary terms