Phone validation and compliance
What is an HLR lookup?
Also called: Home Location Register lookup, HLR query
An HLR lookup queries a mobile network's Home Location Register, the database holding subscriber records on GSM and UMTS networks, to ask about a mobile number's status, such as whether it is registered and which network serves it. It works only for mobile numbers, and many networks restrict or fake the answers.
HLR queries travel over the SS7 signalling network that carriers use between themselves. Because SS7 has been abused for tracking and fraud, many operators now filter these queries, return cached data, or answer the same way for every number. Results differ widely by country and network.
Newer networks also keep subscriber data elsewhere: the HSS on 4G and the UDM on 5G. Services sold as HLR lookup often combine a real query where one is possible with database data where it is not.
Treat any service promising that an HLR lookup proves a number is live and in someone's hand with caution. At best it reflects the network's view at the moment of the query.
How SimpleVerifier handles it
SimpleVerifier does not do HLR lookups. The Email + Phone plan runs a carrier and line-type lookup through Telnyx, which tells you the carrier and whether the number is mobile, landline or VoIP. It does not tell you whether a number is switched on or in service.
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By SimpleVerifier Team · Last reviewed 2026-10-13 · All 50 glossary terms