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How Often Should You Have Your Database for Bulk SMS Updated?

Companies deciding to employ SMS marketing strategy want to create effective texting lists. For this purpose, it is crucial to verify that numbers from the phone’s database are relevant. Marketers also want to know if the possible recipient is traveling abroad (to consider roaming costs), if they are currently able to receive a message.

A tool for creating and efficiently managing contact lists is called HLR checking (or HLR lookup). It allows to peer around a Home Location Register ― an information bank that contains all necessary data about the various mobile networks subscribers, such as:

  • phone number associated with a certain SIM card;
  • whether a number is in service;
  • has it been ported from one network to another;
  • what services connected to a SIM;
  • subscriber’s current location recorded by GSM stations into the Visitors Location Registers;
  • possibility of package data transmission.

This Register is updated whenever the mobile provider enables or disables a new number, so the HRL international phone lookup feature allows you to find out those details. Numbers authorized to use the GSM core network are stored in the base for the period of validity of the subscriber’s connection to them. Contacts identified as no longer used are deleted from the database.

Accessing the database provides comprehensive information on a certain contact, thus eliminating erroneous sending. HLR lookup dynamically contacts an operator’s central database, sends a query to a network’s HLR and returns useful reports. To upload such a report, which can be further analysed, it is necessary to select the HLR filter. Such a request doesn’t infringe the principles of personal data legitimate use of and doesn’t conflict with the GDPR norms.

How Often Should You Clean Your Mobile List?

It is considered a good practice to clean up your contact list regularly ― to get rid of invalid numbers. Everything depends on the frequency of updating the contact base and its volumes. For the lists containing a substantial number of contacts (over 20k), we recommend validating numbers every time before you send out mass texts, as well as quarterly or even monthly. However, before each not a big-scale campaign ― to obtain accurate data on its cost and reduce the latter is feasible. For the BSG clients using the API, the automated HLR check can be configured for each new contact. The results are saved, therefore, there is no need to check contacts before the next messaging.

Why HLR Lookups Are Necessary

Just like any database, bulk SMS lists may contain inaccurate, duplicate entries, erroneous provider data. The situation grows worse since the texting lists compilers often cannot be positive about a certain number belonging to a particular operator. Consequently, messages get much more expensive, and they simply might not reach the recipient. On the contrary, validating your list ensures that you will always reach out to the right person.

Sorting out databases containing millions of numbers manually is a challenging task. Therefore, it makes sense to use the HLR checks in your online contact list management, as well as to get MNP data to ensure your contacts are purely up-to-date. Moreover, you can preliminarily get the duplicates and incorrect numbers out of your list yourself before uploading it for HLR lookup. All numbers will be displayed in numerical format without unneeded spaces and characters.

Key reasons to utilize the cell phone carrier lookup are:

  • compilation of the clean and reliable customer database;
  • handling the problems related to mobile number portability
  • cost cutting by dispatching SMS to the subscribers being online and able to read them.


Checking your numbers ensures you reach out exactly to your consumers and get maximum returns from your SMS marketing campaign. You will not overpay for the inactive numbers and prevent an increased charge if a number is served by another mobile provider. Keep in mind that an advanced business texting software such as BSG incorporates HLR lookups as part of its robust bulk SMS service. We carry out the lookup against the databases of over 500 providers globally. Our solution is perfect to keep only active subscribers in your contacts. Delivering your SMS to more real people adds more value to the entire business’s marketing strategy moving it to the next level.