# Internal Number

The Internal Number module enables extension-based dialing within your phone system. Think of it as creating shortcuts that let users call each other or reach specific features using simple extension numbers.

![Internal Number module appearance](/docs/phone-system-guide/modules/img/internal-number-module.jpg)

## Setting It Up {#setting-it-up}

![Internal Number module configuration interface](/docs/phone-system-guide/modules/img/internal-number-settings.png)

When configuring an Internal Number module, you'll need to provide:

1. **Name**: A descriptive name for the extension, such as:
   - "Sales Conference Room"
   - "Support Team"
   - "Main Reception"

2. **Number**: The 1-4 digit extension that users will dial to reach this module. Pick it from the list of unused internal numbers you've added under **Numbers > Internal Numbers**.

3. **Is a Private Number**: This toggle belongs to a system-linking feature that is no longer available. Leave it off.

:::note
Extension numbers must be unique - you can't use the same extension number for multiple Internal Number modules. Manage your available extension numbers in the Internal Numbers tab of the Numbers menu.
:::

## Practical Example {#practical-example}

Here's a common way to use the Internal Number module:

![Example of Internal Number module usage](/docs/phone-system-guide/modules/img/internal-number-example.jpg)

In this example, an Internal Number module is connected to a conference room. Users with the phone system app or using a SIP account can dial the extension number to join the conference directly.

:::tip[Common Uses]
Internal Number modules are perfect for:
- Creating quick-dial extensions for team members
- Setting up easy access to conference rooms
- Providing short numbers for frequently used features
- Creating a simple internal directory system
- Showing as the internal caller ID when a user calls another extension (chosen in the user's contact method settings)
:::