Can you receive calls on a 3CX extension if the registration is lost?

In a 3CX system, the registration of an extension is crucial for it to effectively receive calls. When an extension is registered, it actively communicates with the 3CX server, allowing it to receive incoming calls, signaling, and real-time updates. If the registration is lost, the server has no way to recognize or route calls to that specific extension.

Consequently, without proper registration, the extension does not exist in the server's access control, leading to a failure in receiving any incoming calls. This is essential for maintaining call quality and ensuring that features such as call forwarding and voicemail are operational. While there might be some limited capabilities for internal calls depending on specific configurations, generally speaking, the lack of registration means no calls can be received at all.

Understanding this principle is key when managing a 3CX system, as it underscores the importance of maintaining a stable connection between extensions and the server for full functionality.