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What is HLR lookup?

What is an HLR lookup?

HLR stands for Home Location Register.

HRL lookup is a service that allows organisations to verify that any mobile phone number (MSISDN) is correct and active before either calling or sending a message to the number.

It’s most commonly used to clean up customer databases.

An HLR lookup interrogates a live database of mobile numbers to query the status of a number on the network.

An HLR is a database of all mobile phone numbers on a mobile network. The database includes up to date information about the status of the mobile number, crucially whether it is an active number or not.

The database is updated in real time, so always contains the most up to date information on every mobile number globally.

Why would you do an HLR lookup?

By conducting an HLR look up, you are able to ascertain whether a number is active or not before sending them a text or calling them.

By avoiding sending text messages to dead numbers, companies can reduce their SMS and phone bill and improve efficiency.

Most SMS API companies charge for undelivered text, so there’s a good reason to check your mobile database before running an SMS marketing campaign or in fact sending non-marketing texts too.

What information does an HLR lookup provide?

HLR uses the SS7 network to access quite a wide range of information on a mobile phone number.

It provides the following information.

  • Phone number validity
  • Whether the number is currently connected,  unconnected or has never been registered
  • Mobile Country code
  • Mobile network name
  • Is the number ported from one network to another?
  • Is the mobile number roaming or in the country of registration
  • Whether the number is switched on or is switched off / out of range

How much does HLR look up cost?

Pricing depends on the volume of HLR lookups

A quick trawl of HLR lookup providers reveals that there’s quite a range of prices available, so it’s definitely worth shopping around to get the best deal.

The most expensive HLR look up provider charged around £0.00540 per lookup. (£5.40 per 1000)
The lowest cost provider was charging £0.0042 (£4.20 per 1000)

HLR lookup providers and cost comparison

HLT Lookup Provider Cost per HLR lookup £0.0043
Data Soap £0.00540
Send Mode £0.0042 £0.009
SMS Factor £0.009
Atom Park £0.0055 £0.013
Commpeak £0.0034
TMT Analysis £0.0035
Click Sumo £0.0052
SMS API £0.006

Benefits of using an HRL lookup service?

There’s a surprising number of reasons for using an HLR look up service.
Here are the main use cases

Maintain an up to date customer database
This is particularly important for large businesses that operate call centres where staff costs are massive.

The cost in wasted time for call centre workers calling dead numbers could be the difference between a business being viable or not.

Fraud prevention and detection
Banks frequently use an HLR lookup provider to help determine whether an overseas purchase or cash withdrawal is likely to be legitimate or fraudulent.

The HLR look up at the point of purchase will determine whether the mobile phone is roaming or not. If the phone is out of its home country and in the same location as the transaction, then it’s likely to be authorised by the account holder.

Telephony routing
Call service providers can use the location data provided by an HLR service to determine the most efficient and cost effective routing for its customers.

Validating phone numbers on web forms
Genuine enquiries can be easily differentiated from spam by doing an HLR lookup on the number entered into a web enquiry form.

This can save time in preventing calling non-existent numbers.

Can an HLR service be used to assist spammers and scammers

Unfortunately an HLR lookup service provides an opportunity for scammers to create a database of prospects at very low cost.

A fraudster or spammer could easily run a HLR lookup on a database of randomly generated numbers.

The results provide them with a ready made database of ‘prospects’ that they can call and text.

Targeting specific number ranges would allow them to increase their chances of obtaining live numbers and reducing their HLR costs.

It’s a depressing thought.

It’s up to the HLR providers to conduct adequate due diligence on their customers and immediately stop any suspicious looking activity.

Are there any privacy issues with an HLR lookup service?

An HLR service provides location data. So the location of any phone can easily be identified.

By anyone at any time.

This isn’t a restricted service into which you have to opt in.

If you have someone’s mobile number and their phone is on, you can find out where they are.

There’s no option to opt out of being on the HLR database.

Sophisticated fraudsters could use this information to target people who are not at their home address. Criminals could use this information to target properties while the owners are away.

It’s troubling and raises questions about whether HLR services should be unrestricted, as they are currently.

Is the use of an HLR lookup service GDPR compliant?

Yes, HLR services are GDPR compliant. There are no issues that you  need to worry about.

This no personal data that is transmitted except for the mobile number which does not have a name of other personal details attached to it.

Is it legal to use an HLR lookup service?

Yes it’s perfectly legal to use an HLT lookup service and there are dozens of potentials suppliers to choose from.

See the table above for some of the main providers.

Does The SMS Works offer an HLR service?

No, we don’t offer it. We only offer an SMS gateway service.

Customers sending texts to UK numbers do not get charged for failed texts, so there’s no cost saving benefit in checking whether a number is live or not before sending the message.

If the number is wrong, the message fails and there is no charge.

If you’d like to explore this, feel free to set up a test account.  We’ll add 50 free credits for testing.

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author avatar
Henry Cazalet Managing Director
Co-founder and Director of The SMS Works, a low cost and powerful SMS API for developers. About Henry