Did you know that between 2% and 5% of mobile numbers change every year? The HLR lookup to validate phone numbers is the tool you need to keep your databases updated and improve the effectiveness of your communication campaigns.

In this article you will learn everything you need to know about the HLR lookup system, from its technical basics to its practical application. We will show you step by step how to interpret the results and avoid common mistakes when verifying phone numbers.

The HLR lookup allows you to:

1. Validate in real time if a number is active
2. Detect the country of origin of any phone number
3. Identify the network operator associated with the number

All this for approximately €0.006 per validation. By using this service, you will significantly reduce the costs of your SMS campaigns, ensuring that you only contact active and valid numbers.

For companies targeting specific regions, knowing the origin of the phone number is critical. With tools such as those offered by verificaremails.com, you can obtain crucial information about the location and status of the number, without worrying about legal issues, as this service is fully compliant with GDPR regulations.

Remember that by verifying your mobile numbers before starting a campaign, you will improve the deliverability of your messages and optimize your communication investment. You will recover your investment in validation from the first mailing you send.

HLR system fundamentals and architecture in 2025

The Home Location Register (HLR) functions as a central database that stores all active mobile subscriber information on a network. In essence, it acts as the “digital ID” of your SIM card, allowing your operator to know who you are and what services you have contracted.

What is the Home Location Register (HLR) and how is it structured?

The HLR is a master database that manages subscriber information for mobile networks, especially in 2G and 3G technologies. We explain the permanent data it stores:

• The IMSI (International Mobile Subscriber Identity): the unique identifier of each SIM card.
• The MSISDN (Mobile Station International Subscriber Digital Network): the subscriber’s telephone number.
• Information on contracted services and activation status
• Subscriber location data for routing calls and messages

When using an HLR lookup service to validate phone numbers, you can query this information to determine the validity and origin of a number.

Differences between HLR, VLR and MSC in mobile networks

Remember that while the HLR maintains permanent information on all users of a network, the VLR (Visitor Location Register) temporarily stores data on active subscribers in a specific geographic area. This difference is fundamental: the HLR is the complete database, while the VLR manages temporary information of users in a specific area.

On the other hand, the MSC (Mobile Switching Center) handles call routing and mobile subscriber management in collaboration with databases such as the HLR and VLR. When you receive a call, the MSC queries the HLR to locate you.

How country and network information is stored in the HLR

Country and network information is mainly stored using identification codes. When you use an HLR lookup to detect the country of a phone number, the system queries these codes to identify its origin.

We recommend you to keep in mind that by 2025, although HLR is still essential in 2G and 3G networks, in more advanced technologies such as 4G and 5G it has evolved to HSS (Home Subscriber Server), offering similar functionalities but with higher efficiency. However, the basic principles of number verification and country detection are still applicable in modern HLR lookup services.

Identifying the country of origin of a phone number is crucial to optimize your communication campaigns. Our number verification service helps you get this information quickly and efficiently.

Detection of country and mobile network using HLR Lookup

The HLR query allows you to access mobile network subscriber information in real time, facilitating the identification of the country and operator associated with a telephone number. This functionality is essential to keep your databases updated and clean.

Use of MCC and MNC codes for country and operator identification

To accurately detect the origin of a number, the HLR system uses two fundamental codes:

1. The MCC (Mobile Country Code): a three-digit code that identifies the subscriber’s country. For example, Spain is assigned MCC 214.
2. The MNC (Mobile Network Code): a two or three digit code that identifies the mobile network within that country. In Spain, Movistar uses MNC 07.

The combination of both codes (MCCMNC) provides a unique identification of the mobile network. For example, MCCMNC 21407 corresponds specifically to Movistar in Spain. Using the verifyingemails.com service, you can check this information to confirm the authenticity of any number.

Practical example: detecting country of an ambiguous prefix number

Have you ever been confronted with numbers with confusing prefixes? The HLR lookup is particularly useful in these cases. Some prefixes can vary in length (from one to three digits) and are easily confused with the telephone number.

For example, to know where a call is coming from, you must correctly identify the international prefix, such as +34 for Spain or +1 for the United States and Canada. The HLR system helps you resolve this ambiguity automatically.

How to interpret ‘network’ and ‘country’ results in the HLR API

When querying via API HLR, you will get several parameters in JSON format. The most relevant fields include:

• country: Full name of the country of the number consulted.
• country_prefix: Numeric country prefix
• network: Name of the current mobile network
• original_network: Original network if number has been ported
• ported: Indicates whether the user has changed operator while keeping his number.

Remember that this information allows you to verify the validity of mobile numbers with worldwide coverage and optimize your message sending. If you are going to use number validation services on a regular basis, we recommend using the API to automate the whole process.

Materials and Methods: API HLR Lookup Testing

To perform effective testing with the HLR lookup system, you need a reliable verification platform. Below, we will show you how to set up and use these services step by step.

Test environment configuration with Verificaremails

To implement HLR checks, follow these steps:

Step 1: Register at verificaremails.com and complete the validation process.
Step 2: Generate your API key from the configuration section of your account.
Step 3: Save your credentials (email and token) in a safe place.

This platform offers you several options to validate phone numbers:

• Individual verification
• Bulk email address file-based verification check.
• API integration to automate the process

The best thing is that the whole validation process is done without sending real messages to your contacts, thus preserving privacy.

Querying a number with API HLR Lookup: parameters and response

Once you have your credentials, you can perform individual queries via GET requests. A basic example would be:

curl -X GET "https://www.verificaremails.com/api/v1/hlr?phone_number=XXXXXXXXXX" -H "apikey: TU_CLAVE_API"

The response is returned in JSON format with structured information:

{
  "status": "success",
  "data": {
    "phone_number": "XXXXXXXXXX",
    "valid": true,
    "carrier": "Movistar",
    "country": "ES",
    "mcc": "214",
    "mnc": "07"
...
  }
}

The parameters you should check are:

• validindicates whether the number is valid
• countrycountry of the number
• carrier: mobile operator
• mcc and mnc: codes identifying the specific network

Bulk validation of numbers from CSV file

If you need to verify large volumes of numbers, we recommend file-based validation:

Step 1: Prepare a CSV, XLS or XLSX file with the numbers to be validated.
Step 2: Make sure that each number appears in international format (+34XXXXXXXXXXXX).
Step 3: Place the numbers in a single column of the file.
Step 4: Upload the file to the platform from the “Validation” section.

After processing, you will receive a file with the results, which will include:

• The original columns
• Number status (valid/invalid)
• Country of origin
• Current operator
• Portability information

For best results, we recommend using lists with less than 150,000 records per file. This method is perfect for cleaning your databases before starting communication campaigns, avoiding unnecessary costs in messages addressed to inactive numbers.

If you have questions about how to implement any of these methods, our support team will be happy to help you.

Technical limitations and common errors in HLR Lookup for phone number validation

Despite the advantages of the HLR lookup to validate phone numbers, this system has some limitations that you should be aware of. As mentioned above, between 2% and 5% of mobile numbers change annually, which affects the accuracy of your databases.

Frequent errors: HLR_ABORT, CALL_BARRED, TELESERVICE_NOT_PROVISIONED

Have you encountered errors when verifying numbers? These are the most common ones:

• HLR_ABORT: Indicates an interruption in communication with the operator’s HLR.
• CALL_BARRED: The number has restrictions that prevent the query.
• TELESERVICE_NOT_PROVISIONED: The service is not enabled for that number.
• Unknown Subscriber/Absent subscriber: Signals that the number does not exist.
• No response/system failure: The operator’s network has not responded.

Remember that in case of error, it is not advisable to immediately discard the number, as it could be due to temporary network or device failures. We recommend that you perform a second check before deleting the contact for good.

Response latency and coverage by country

The speed of response varies significantly by country and operator. When checking a list of numbers, the response can take up to an hour, as queries are processed through different mobile networks with different speeds.

To ensure optimal performance, platforms such as Verificaremails set limits of 10 requests per second. This avoids temporary or permanent blockages that could affect your verifications.

Limitations in number portability detection

Number portability represents a major challenge. When users keep their number when switching carriers, it complicates the accurate detection of the current provider. If the HLR query is not properly integrated with the portability database, it may return details of the old carrier instead of the new one.

On the other hand, you will be interested to know that the HLR information refers exclusively to the telephone number and not to the user’s personal characteristics. This limits its use for certain marketing purposes but ensures compliance with privacy regulations, a fundamental aspect for your business.

Periodic verification of your databases is therefore essential to maintain the quality of your contact information. The investment in these checks will be quickly recouped by improving the effectiveness of your campaigns.

Conclusion

The HLR lookup system has established itself as an indispensable tool for any company that needs to keep telephone databases up to date. Throughout this article we have shown you both its technical fundamentals and its practical application for mobile number validation.

The ability to verify numbers in real time before initiating communication campaigns saves significant resources. The approximately €0.006 per validation represents a minimal investment compared to the cost of sending messages to inactive or non-existent numbers.

We recommend that you periodically check your databases, since between 2% and 5% of the numbers change annually. This practice is essential to maintain the quality of your contacts and maximize the return on your communications investment.

Verificaremails offers a complete solution that allows you to accurately detect the country of origin, operator and status of any phone number. In addition, its support for individual and mass validations makes it easy to adapt to any workload.

Although errors such as HLR_ABORT or CALL_BARRED may occasionally occur, they should not discourage you from implementing this technology. On the contrary, knowing these limitations will allow you to interpret them correctly and get the most out of the tool.

The investment in verifying your phone numbers will be recovered from the first campaign. Register for free on our platform and try it out.

Remember that having clean and updated data not only improves the deliverability of your messages, but also protects your brand’s reputation and optimizes every euro invested in your communication campaigns.

FAQs

Q1. What is the HLR Lookup and what is it used for?
HLR Lookup is a tool for validating cell phone numbers in real time. It is used to detect whether a number is active, identify the country of origin and the network operator, which helps to maintain updated databases and improve the effectiveness of communication campaigns.

Q2. How much does it cost to perform an HLR consultation?
The approximate cost of an HLR query is €0.006 per validation. This investment is minimal compared to the savings of avoiding sending messages to inactive or invalid numbers in communication campaigns.

Q3. What information does an HLR query provide?
An HLR query provides data such as the validity of the number, the country of origin, the current network operator, whether the number has been ported, and the MCC (Mobile Country Code) and MNC (Mobile Network Code) codes that identify the specific mobile network.

Q4. What are the limitations of HLR Lookup for validating phone numbers?
Some limitations include errors such as HLR_ABORT or CALL_BARRED, variations in response latency by country and operator, and difficulties in accurately detecting number portability. In addition, between 2% and 5% of mobile numbers change annually, which affects the accuracy of the databases.

Q5. How can a massive validation of telephone numbers be performed?
To validate large volumes of numbers, you can use the bulk validation function offered by platforms such as verificaremails. This process involves preparing a CSV, XLS or XLSX file with the numbers in international format, uploading it to the platform, and receiving a results file with the validated information for each number. You can also use the API to validate phone numbers if you want to automate the whole procedure.