HLR Lookup API

HLR Lookups is a technology to check the status of any GSM cell phone number. By making a query to the Home Location Register, the lookup service determines whether that number is valid, whether it is currently active in a mobile network, and if so which network, whether it was ported from another network, and whether it is roaming. The query will also return meta information such as the IMSI, MSC, MCC and MNC.

With the emergence of Mobile Number Portability, cell phone subscribers can now keep their number when they change carriers.
This of course is highly convenient for customers, but it has also created a major challenge: now, it is much harder for businesses to guarantee the successful delivery of text messages, due to the quality of their customer database – it is often full of invalid or deactivated phone numbers. The result? A pricey waste of time and money. HLR Lookup is a service that gets around this.

HLR stands for Home Location Register. It is essentially a central global database of all the cellphone subscribers registered with a particular mobile network.
In is constantly updated in real-time, HLRs hold the most accurate, up-to-date information on any cell phone subscriber anywhere in the world. An HLR stores details of every SIM card the mobile phone operator issued. Each SIM has a unique identifier, called an IMSI, which is the primary key to each HLR record.

Information that can be obtained in real-time through HLR Lookups:

• The name of the mobile network operator to which that number currently belongs
• The country in which the network operator and the phone customer are located
• The MCC (Mobile Country Code), the MNC (Mobile Network Code), IMSI (International Mobile Subscriber Identity) and MSC (Mobile Switching Center) of the phone number
• Whether the number is currently active, has been deactivated, or was never registered — and therefore whether the number is valid or invalid
• If so, the name of the network to which the number belonged when first registered
• Whether a subscriber is roaming, which country they are roaming in, and what network they are currently logged on to (information obtained through the MSC address currently serving the number)
• Whether the phone is switched on or temporary errors could prevent the delivery of an SMS — for example, if the phone is turned off or out of coverage for an extended time — referred to as an “Absent Subscriber”
• The identification of the network even if an error such as “Absent Subscriber” is returned

• Qualitative mobile number databases, removing invalid and deactivated numbers, enabling businesses to lower their costs by sending SMS texts to valid numbers only
• Enhanced marketing function of an organization by allowing them to target an up-to-date database of customers, clients, alumni, or members
• Better revenue margins and broader service coverage
• Better service when roaming
• Traffic facilitation and routing optimization for VOIP, SMS, and voice calls by determining a subscriber’s home network
• Reduction of Mobile Number Portability issues and interworking fees to a minimum
• Higher accuracy of network billing by identifying the network a mobile number currently belongs to
• Real-time network information, including whether the number is ported
• Troubleshooting SMS delivery problems
• Distinction between invalid numbers, numbers experiencing a temporary problem, and handsets that are switched off