---
title: "Error 003 SIP Registration Failure"
slug: "error-003-sip-registration-failure"
updated: 2026-05-11T10:52:09Z
published: 2026-05-21T21:28:00Z
canonical: "help.8x8.com/error-003-sip-registration-failure"
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.

# Error 003 SIP Registration Failure

## Symptom

Your Panasonic KX-TGP600 DECT phone is receiving the following error, *Error 003: Not registered.*

## Applies To

- Panasonic KX-TGP600 DECT Phones

## Resolution

> [!NOTE]
> Note:
> 
> This product has reached end of life. [Create a Case with 8x8 Support](/support/docs/create-a-case-with-8x8-support).

## Cause

This error may result from a bad configuration, failed handset pairing, a device requiring pairing, or a non-activated or offline base unit.