How can I check my landline wiring?

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Having problems making or receiving calls on your phone at home? Here’s how to check if your service is working from your main BT socket, and your test socket.

Main phone socket

Main phone socket

Start by finding your main socket – it's the socket your phone line connects to as it enters your home. It should look like one of these:

Single master socket and dual master socket

  1. 1

    Remove anything plugged into the socket, e.g. broadband filters, line doublers, or extension cables

  2. 2

    Connect a phone (ideally a corded handset, and not a DECT or portable phone) directly to the socket

  3. 3

    Pick up the handset, and try to make a call

Test socket

Test socket

If your phone works in your test socket, there are a few tests you can try:

Single master socket screws

  1. 1

    Unplug your phone from the phone socket

  2. 2

    Carefully unscrew the two screws on the bottom half of the faceplate

  3. 3

    Gently remove the lower half of the faceplate – be careful not to disturb any cabling behind it (if wires are already loose behind the faceplate, this could be the cause of your problem)

  4. 4

    Plug your phone into the test socket

BT test socket

If your phone works in your test socket, check these elements:

f your phone works in your test socket, check these elements:

    disconnected extension sockets and cables. Check your extension is plugged in correctly, and nothing has become dislodged


    damaged extension sockets and cables. You may need to replace extension kits or consider using a cordless phone


    faulty equipment connected to your line. If you can, test all your equipment one by one in your test socket. Once you've found the faulty equipment, remove it from your line


    faulty broadband filters. Check all your filters with a phone you know is working 


    broadband routers. If you only get the problem when you connect your broadband router to the line (and you've already checked with a spare filter), let us know.


    too many phones connected. As a general rule, phone lines are designed to work with up to four phones or devices connected to the line. If you've got more, test with only four devices connected

Still not working? Take a look at our tips on how to fix home phone faults.

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Last updated: 8/8/2018
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Thank you.

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Glad to hear it.

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