---
title: "Unable to Assign Extension Number to a User"
slug: "unable-to-assign-extension-number-to-a-user"
updated: 2026-04-17T16:02:08Z
published: 2026-05-21T21:26:45Z
canonical: "help.8x8.com/unable-to-assign-extension-number-to-a-user"
stale: true
---

> ## 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.

# Unable to Assign Extension Number to a User

## Symptom

Unable to assign a particular extension number to a user from Admin Console. An error is shown, *"User settings saved with errors. Failed at extension update."* or an error indicating that the extension already exists. Other extension numbers (such as the suggested extension) can be assigned to the user.

## Applies To

- Admin Console
- Extensions

## Resolution

Use a different extension number.

## Cause

Some extension numbers are reserved for use by the system for use by services. These are not always visible in Admin Console. For example, 601-605 are reserved for Call Park extensions.