---
title: "CNAM Lookups & Number Line Type Determination (VoIP vs Wireless)"
---

CNAM Lookups & Number Line Type Determination (VoIP vs Wireless): SMSRiver

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Telecom Regulations & A2P 10DLC

Published 2026-09-04

•

7 min read

# CNAM Lookups & Number Line Type Determination (VoIP vs Wireless)

Guide to Caller ID Name (CNAM) databases and HLR carrier lookups. Filter non-fixed VoIP virtual numbers from mobile cellular lines before dispatch.

Key Takeaway & Executive Summary

Perform real-time HLR and carrier lookups to identify line types (Mobile vs VoIP vs Landline), eliminating wasted SMS costs on non-SMS-capable numbers.

Dispatching SMS codes to landlines or untrusted virtual VoIP lines wastes budget and increases fraud risk. Carrier lookup APIs inspect centralized telecom databases to reveal true line type, original network operator, and ported status prior to message dispatch.

## Table of Contents

- [Line Type Taxonomy](#section-1)

- [Frequently Asked Questions](#frequently-asked-questions)

## 1 Line Type Taxonomy

- Mobile / Wireless: Cellular SIM cards with SMS capabilities (highest deliverability).
- Fixed VoIP: Enterprise IP phone systems (Skype, Zoom Phone) with limited SMS support.
- Non-Fixed VoIP: Disposable virtual number apps (frequently used by fraudsters).
- Landline: Traditional wired telephone lines unable to receive SMS text messages.

## Frequently Asked Questions • Telecom Regulations & A2P 10DLC

How much does a carrier lookup cost?

Carrier lookup APIs cost between $0.005 and $0.01 per lookup. They pay for themselves by filtering invalid numbers and preventing failed SMS segment charges.

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