--- title: "Phone Number Validation Home Location Register HLR" slug: "home-location-register-hlr" description: "Agents can check the availability of a contact on a mobile network before redialing a phone number." tags: ["masking", "HLR", "Mobile number validation", "HLR Lookup", "Validation", "Number", "Lookup", "Number lookup", "Number validation"] updated: 2025-09-22T16:40:54Z published: 2025-09-22T16:40:54Z canonical: "docs.voiso.com/home-location-register-hlr" --- > ## Documentation Index > Fetch the complete documentation index at: https://docs.voiso.com/llms.txt > Use this file to discover all available pages before exploring further. # HLR Lookup **Who should read this article**: All users Agents can check the availability of a contact on a mobile network before redialing a phone number. Important The HLR Lookup feature is available for contact centers on the Pro plan or higher. ## Use Case: HLR Lookup Voiso's **HLR Lookup**, sometimes called *Mobile Number Lookup*, is a service that allows agents to validate a contact's phone number in real-time. Using the **HLR Lookup** feature, an agent can determine whether the contact is available to take a call. Important Contact your Voiso Account Manager to get the full list of covereage for the HLR Lookup service. ### Benefits HLR Lookup saves an agent time when redialing a number. Sometimes when an agent calls a contact back at an agreed upon time they are unable to reach the contact. Instead of redialing the contact multiple times then requesting that their supervisor check the network for issues, a simple HLR Lookup check enables the agent to determine whether the contact is available or absent. Agents only have to report potential network issues when the HLR Lookup indicates the contact is available but calls are not going through. ## Enabling HLR Lookup This section describes how to enable the **HLR Lookup** feature both for contact centers using Security Access Groups and those that do not. ### With the Security Access Groups feature If your contact center uses **[Security Access Groups](/v1/docs/administration-security-access-groups)**, the **Display HLR Lookup in WebRTC** permission in the **Outbound** section is granted by default for the **Agent** Security Access Group. The HLR Lookup button is automatically available in the **[Agent Panel](/v1/docs/agent-panel-outbound-calls)**. ![HLR Lookup SAG Display HLR Lookup in WebRTC HLR Lookup](https://cdn.document360.io/44ae307a-3737-4fbf-98e0-9b888deb90dc/Images/Documentation/HLR%20Lookup%20SAG%20Display%20HLR%20Lookup%20in%20WebRTC%20HLR%20Lookup.png) You can also create a custom Security Access Group that enables or disables this feature. To manage Security Access Groups, in the Voiso navigation bar, navigate to **Administration > Security access groups**. ### Without the Security Access Groups feature If your contact center does not use Security Access Groups, enable the **Allow HLR lookup** permission in the **Add user** or **Edit user** page. ![HLR Lookup No SAG Add User Allow HLR Lookup](https://cdn.document360.io/44ae307a-3737-4fbf-98e0-9b888deb90dc/Images/Documentation/HLR%20Lookup%20No%20SAG%20Add%20User%20Allow%20HLR%20Lookup.png) To manage [user](/v1/docs/users-users) permissions, in the Voiso navigation bar, navigate to **Users > Users**. If you want to create bulk users with the **Allow HLR lookup** capability, import a CSV with this permission indicated with a `y`. To learn about importing user accounts, refer to [Importing user accounts](/v1/docs/users-users#importing-user-accounts). ## How to make an HLR Lookup request Your contact center agents use the Voiso **Agent Panel** to perform an HLR Lookup request. 1. In the **Agent Panel** home screen, click the **Call history** button to display the **Call history** screen. 2. On the **Call history** screen, find the number of the contact to be called. 3. Click the *kebab menu* to display the **Call details** screen. 4. To make the HLR Lookup request, click the **HLR Lookup** button. 5. The HLR Lookup result is displayed next to the number. You can now decide whether to make the call or not. | HLR Lookup result | Description | | --- | --- | | Available | The number is active and can be called. | | Absent | The number is inactive and should not be called. | | Unavailable in country | HLR Lookup is unavailable in the country where the number is located. | | Is a landline number | The number is a landline, not a mobile number. HLR Lookup does not support landlines. | #### Available number ![HLR Lookup Agent Panel Number Is Available](https://cdn.document360.io/44ae307a-3737-4fbf-98e0-9b888deb90dc/Images/Documentation/HLR%20Lookup%20Agent%20Panel%20Number%20Is%20Available.gif) #### Absent number ![HLR Lookup Agent Panel Number Is Absent](https://cdn.document360.io/44ae307a-3737-4fbf-98e0-9b888deb90dc/Images/Documentation/HLR%20Lookup%20Agent%20Panel%20Number%20Is%20Absent.gif) ### What if the HLR Lookup button is disabled? The **HLR** button is disabled when the phone number is from a country that does not support access to HLR or the phone number is not a mobile number. #### Unavailable in country ![HLR Lookup Agent Panel Number Is Unavailable In Country](https://cdn.document360.io/44ae307a-3737-4fbf-98e0-9b888deb90dc/Images/Documentation/HLR%20Lookup%20Agent%20Panel%20Number%20Is%20Unavailable%20In%20Country.png) #### Number is a landline ![HLR Lookup Agent Panel HLR Button Disabled Landline](https://cdn.document360.io/44ae307a-3737-4fbf-98e0-9b888deb90dc/Images/Documentation/HLR%20Lookup%20Agent%20Panel%20HLR%20Button%20Disabled%20Landline.png) ## Number masking The **HLR Lookup** feature supports [number masking](/v1/docs/administration-security-access-groups#number-masking). Agents can lookup a phone number even if the number is masked in the **Agent Panel**. Comma-Separated Values. A data file format where the content is structured in tabular form. Fields (data values) are separated by commas. Rows (records) are separated by line feeds. Voiso supports UTF-8 format for CSV files. CSV files allow interchange of data between spreadsheet applications, text files, and database. It is a common format for importing and exporting data. Each row represents a record. Each value represents an attribute. ## Related - [Getting started](/agent-panel-getting-started.md) - [Outbound calls](/agent-panel-outbound-calls.md)