IMSI and HLR-requests


HLR-request (stands for Home Location Register): represents the way to determine the current state of the subscriber’s number. The request is made to the database of the cellular company that services the number.

When sending a request, the system does not bother the subscriber and does not inform him in any way that someone is interested in the current status of his number.

The HLR-request allows you to find out:
Номер абонента
Данные абонента
Сеть SS7

If the phone number exists, and - if it exists - if the number is active.

IMSI - what is it?

IMSI (stands for International Mobile Subscriber Identity) – is an individual number assigned to each subscriber. When subscriber connects a mobile operator, his IMSI is read by the system, after which he is identified.

Using IMSI allows you to secure the transfer of passwords, registration codes and other similar data by SMS.

More precisely, IMSI and HLR-requests allow

  • to check the SIM-card of the client when he makes any payment. If fraudsters will try to
    use a client’s duplicated SIM card, a confirmation code will not be sent to their number.
  • to check the SIM-card when the client confirms other actions by SMS. Such actions
    include: sending the authorization code, getting information about the account status,
    login confirmation, receipt / withdrawal of funds
  • to compile a lists of customers for calling. Customers can be in different time zones,
    which is why it’s important to know which is the most favorable time for a call. Also,
    IMSI- and HLR-requests make it possible to find out whether the subscriber is active or
    inactive, so that inactive numbers are not dialed.
  • to get the DEF code. Some customers’ numbers can be saved without operator’s codes,
    which will cause certain difficulties in conducting SMS mailing. Getting the DEF-code of
    the phone number allows you to bypass all these difficulties.