HLR or Home Location Register is a centralized data system, which contains complete information about the subscribers of all GSM operators. HLR is widely used by SMS aggregators and mobile operators to improve the routing of SMS traffic, as well as complementary to cloud based two factor authentication to verify the validation of mobile numbers. It allows you to find out most of the important information about the subscriber in order to prevent ineffective mailings.

The HLR register contains information about all GSM network subscribers. It updates automatically every time the mobile operator activates new numbers. These numbers are stored in the database until they are no longer used. When the system recognizes that phone numbers are no longer available, it removes them from the database. Checking phone number validation with the HLR database application is completely anonymous. Subscribers, whose numbers are verified by HLR Lookup, will not know about it.