---
title: "Reserve an Extension Number in 8x8 Admin Console"
slug: "reserve-an-extension-number-in-8x8-admin-console"
updated: 2026-05-17T17:52:01Z
published: 2026-05-21T21:25:40Z
canonical: "help.8x8.com/reserve-an-extension-number-in-8x8-admin-console"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.8x8.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Reserve an Extension Number in 8x8 Admin Console

## Objective

Reserve an extension number in Admin Console.

## Applies To

- Admin Console
- Extensions

## Procedure

1. Log in to [Admin Console](https://login.8x8.com).
2. Select **Extension Numbers**.
3. Select **Reserve Extension Numbers** (top right).
4. **Complete the fields**, as seen below. ![](https://cdn.us.document360.io/e3a59e39-abd3-4423-964c-0a4008dc5673/Images/Documentation/17266?sv=2026-02-06&spr=https&st=2026-11-03T23%3A18%3A01Z&se=2026-11-04T00%3A18%3A01Z&sr=c&sp=r&sig=Nkd0HpfzLBqJkyTZgMDDyvxdXHfsp31sMzibYDJkQbY%3D)
5. Select **Save**.

## Best Practice

It is best practice that the below extension numbers marked as reserved are not used. Some of the Reserved extensions are already assigned to backend services. These extension assignments cannot be removed/deleted or reassigned.![](https://cdn.us.document360.io/e3a59e39-abd3-4423-964c-0a4008dc5673/Images/Documentation/17265?sv=2026-02-06&spr=https&st=2026-11-03T23%3A18%3A01Z&se=2026-11-04T00%3A18%3A01Z&sr=c&sp=r&sig=Nkd0HpfzLBqJkyTZgMDDyvxdXHfsp31sMzibYDJkQbY%3D)

## Additional information

If you have a site set up with internal dialing codes, and the dialing code is XYZ, extensions such as XYZ555 for example are still reserved. For more information, see [Configure Cross-Site Dialing in Admin Console](/support/docs/configure-cross-site-dialing-in-admin-console).