Why is there static on my phone line?

We're sorry that you're hearing static or other interference on your phone line. Here's our step-by-step guide to sorting it out.

  • Check your phone is set up correctly. Specifically, a microfilter must only be used for a wall socket with a single hole. For wall sockets with two or more holes, do not use a microfilter.

Wall sockets with one hole - use a microfilter!

Wall sockets with two holes - microfilter not needed

  • Disconnect telephone equipment one at a time, while listening on the phone. This includes other phones, answering machines, DSL modems, fax machines, computers connected via dial-up, and alarm systems.
  • Each time you disconnect something, listen out for whether the static goes away. If the static stops, then the last piece you disconnected is likely causing the interference. Try plugging the offending piece of equipment into a different jack if possible.
  • If this happens, work out whether the issue is with the phone / device or the jack. To do this, plug the phone or device into a different jack. If the issue is with your jack, you need to replace it.
  • Try changing channels on your cordless phones. If you're experiencing static on your cordless phone, there may be too many signals on the frequency. Look for a Channel button on your handset or on the base station. Change channels until you find one clear of interference.
  • Move or disable interfering equipment. Certain electronics impede on the frequency used by cordless phones, and moving or turning off this equipment may help your signal. Try to keep cordless phones out of your kitchen, as microwaves will often disrupt the signal. Baby monitors, Bluetooth devices, and other cordless phones can also all cause interference.

If none of these work, you could try carrying out a test socket test. Your test socket bypasses the internal wiring in your house and connects directly to the Openreach line outside. It therefore can help identify whether there's an internal issue with your home wiring, or instead a fault in your local area.

You can find your test socket inside your master socket. The master phone socket is the main socket where the phone line enters your home, usually found in the hallway near the front door.

Master sockets that have two ports, or one port with a horizontal line across the front, contain a test socket. But if your master socket has one port without a horizontal line, then you don't have a test socket; if so, please don't carry out the steps below.

To connect to your test socket:

  • Carefully unscrew the faceplate on your master socket with a screwdriver. Or if your master socket doesn't have screws, squeeze the sides of the plate to detach it
  • Carefully and slowly pull the faceplate towards you
  • You'll now see the test socket inside. It will look like the port on the front of your master socket but without any sliding cover
  • Plug your phone into the test socket
  • If your line improves or is resolved while you're connected to the test socket, then the fault is likely to be with your internal wiring. You could fix this yourself, or get an expert in to help resolve it
  • If the line doesn't improve, there's likely and issue with the external wiring or network

If you've tried all these steps and are still having issues, try getting extra advice in our community forum. If you're still having problems, you can get in touch with us:

  • Log in to your online account
  • Click on My Cuckoo
  • Select Support hub
  • Chat to us via your preferred channel
Cuckoo corner 🐣

💡 Fun fact: The 14th April is St. Tiburtius Day, and is traditionally when you will hear the first cuckoo. It's also the date of our annual office party.