How can I check my landline wiring?

In this article

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.

How do I check my main phone socket?

How do I check my main phone socket?

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

Single master socket and dual master socket

  1. 1

    remove anything plugged into the phone 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 phone socket

  3. 3

    pick up the handset and try to make a call

How do I check my text phone socket?

How do I check my test phone socket?

If you’re telephone didn't work when tested in your main phone socket, try using your test socket and follow the same checking procedure as above again.

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

Single master socket screws

  1. 1

    unplug your phone from the phone socket

  2. 2

    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, you should then 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 filters with a working phone


    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 broadband filter), please call us to 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

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