6 minutes to read

What is HLR?

Mobile subscribers often travel around their countries and abroad, change numbers, switch to a new provider while retaining the original number, leave the coverage area or turn off their devices. As a result, marketing delivery reports may occasionally demonstrate significant differences between your list size and the number of messages delivered, as well as between the expected and actual campaign cost.

To prevent those useless spending, before sending anything, it makes good sense to review and clean your contact list. Here it’s time to discover what is HLR in mobile communication. An acronym “HLR” stands for “Home Location Register” ― a database comprising various details about all subscribers of a GSM network, such as:

  • IMSI (International Mobile Subscriber Identifier);
  • MSC (cellular network switch);
  • initial mobile network;
  • current mobile network;
  • current country;
  • call-routing data;
  • user’s service entitlements.

HLR telecom is an element of all 2G and 3G mobile networks. It provides the network mechanism for international and local roaming and cell-to-cell handover of the calls. Home Location Register lookup is a particular telecommunication service from BSG, which dynamically contacts this database on the operator’s part in order to check the sim number validity and status. It is in line with the principles of personal data fair use and GDPR.

How to make an HLR query?

There are two options to perform the HLR lookup ― to enter or upload the phone(s) into the HLR system, or to query our robust API. The first option is available for BSG clients directly from the Web-Interface in their Cabinet. The flow is straightforward and goes as follows:

  1. Select the HRL item from the “Create” or “Products” menu.
  2. Enter the campaign name (edit or leave the autogenerated).
  3. In the Recipients block, add the contacts subject to verification. You can either add the list from your address book, or enter the phone numbers from the clipboard, or upload your list in several common formats. You can immediately automatically clean all duplicates and incorrect numbers from the list before checking it.
  4. Configure and save the additional settings (tariff, email notification).
  5. Click Submit to launch the lookup immediately, or schedule it for a certain time.

After the check is finished, the report will be displayed automatically. It can also be viewed in the Campaign Report tab in the HLR section. It contains the following HLR information on the campaign:

  • name, type, status (with creation and end dates);
  • number of sent requests, contacts identified as relevant and rejected;
  • proportion of delivered requests from the total number of contacts;
  • number of active and inactive contacts, as well as those not active at the time of lookup (no data);
  • number of contacts in roaming and not at the time of lookup;
  • campaign’s technical details;
  • number of ported and non-ported contacts; 

Regarding the last point: the part of the HLR definition is MNP. Many operators support the Mobile Number Portability (MNP) service. It allows to transfer phone number from one operator to another with the SIM card being changed, which means that messages to such ported number will be charged according to the current operator’s rate;

Additional detailed HLR report drills down the statuses of all numbers checked for a specific period. Day-by-day statistics of sent and delivered requests are displayed in graphs. You can download the report and sift through the contacts to download by country and other criteria.

The second, advanced option is available for the clients using BSG REST API. The integration with your client application software comes with additional HLR functions. It allows to make an HLR query directly from your CRM or CMS system, or to configure an automatic HLR query for each new contact. Our API is asynchronous and streaming, which means that the client can make as many API requests as they need, simultaneously from several servers, with no need to wait for requests completion.

HLR verification report is sent and displayed in the same form as it is generated via the web-interface. You can also set the default callback link in the SMPP/API password tab of the Integrations and API section ― in this case, the response for HLR request will be sent automatically to your native platform.

How often to perform HLR validation and when it becomes essential?

We suggest using the mobile HLR check service on a regular basis: to eliminate irrelevant numbers from the contact database and before each bulk SMS messaging. The frequency depends on how often your contact base is updated, as well as on its volume as such.

Sure enough, HLR SMS lookup is quite required when you’re starting out ― when you have just compiled your customer list, before the first messaging. Again, if your contacts base is constantly being increased, this is another important reason to consider our asynchronous API integration ― you will be able to receive the HRL updates on every old and new subscriber in the real time data-driven mode.

However, even if your contact list contains 500―1 000 entries, and you have not considered the API integration yet, you already have a reason to look into the option of the HLR lookup campaign. If there are 2 000 and more contacts in your list, you should perform a Home Location Register check at least every quarter. The rule of thumb is that the HLR lookups should be performed half as often as the messaging campaigns are launched. That is, if you schedule sending bulk SMS online every fortnight, you should carry out the numbers lookup monthly. 

Companies need to make sure new accounts belong to real people. To verify this, an SMS is sent to a mobile phone number — one of the first and critical interactions between customer and company. But surprisingly often, customers enter a number unable to receive texts, and the person is not verified. Not to mention damage to the brand, this rises per-user costs and wastes investment for customer acquisition. That can be avoided with the streaming HLR lookup software — a short one-time step made at the first interaction with an app or service. Verified mobile numbers are also crucial for SMS-based two-factor authentication (2FA) solutions.

Last but not least, the roaming issue is essential in our days, in order to avoid excessive budget spending for SMS (we know that if the subscriber is abroad at the moment, the message cost grows). Equally important it is when your promotional offer directly depends on the subscriber’s current location. It is meaningless to send an offer to the person who is technically unable to accept it being outside the country. Thus, the function of HLR query lies not only in cleaning the list, but it also contributes to accurate customer segmentation.

Now that we have learnt what is HLR, we can see how mobile number HLR verification enhances communication efficiency, conversion rates and customer relationships. Omitting this preparatory step, you might be losing thousands of prospective customers. With effective mobile number lookup from BSG, companies can boost conversion rates and make users happy with the smooth verification experience.