What is the HLR database?
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 the phone number with the HLR application is completely anonymous. Subscribers, whose numbers are verified by HLR Lookup, will not know about it.