---
title: "HLR lookup"
description: "An HLR lookup queries the mobile network’s subscriber database to check whether a number is valid and active, which operator currently serves it (after porting) and sometimes whether it is roaming."
canonical: "https://omnichannels.ai/glossary/hlr-lookup/"
language: "en"
updated: "2026-10-10"
publisher: "BroadNet Technologies"
brand: "OmniChannels.ai"
---

# HLR lookup

Canonical: https://omnichannels.ai/glossary/hlr-lookup/
Language: en
Publisher: OmniChannels.ai by BroadNet Technologies

**Definition:** An HLR lookup queries the mobile network’s subscriber database to check whether a number is valid and active, which operator currently serves it (after porting) and sometimes whether it is roaming.

The Home Location Register stores subscriber records for a mobile network. The SMSC itself uses an HLR query (MAP SendRoutingInfoForSM, defined in 3GPP TS 29.002) to find where to deliver an SMS. A lookup service exposes similar information to businesses.

Businesses use HLR lookups to clean contact lists before a campaign, to route messages to the right operator after number porting, and as a fraud signal during sign-up.

Results vary by country and network. Some operators restrict or block lookups, some return limited data, and newer networks use HSS or UDM rather than a classic HLR. Treat “unknown” results with care rather than deleting numbers automatically.

Personal data rules apply: store only what you need and use lookups for a legitimate purpose.

## Sources

- [3GPP TS 29.002 — Mobile Application Part (MAP) specification](https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1585)