How long is your telephone line?

How to find out the distance from your local telephone exchange


How to find the length of your BT telephone line

How to find the length of your BT telephone line

This BT telephone line test allows you to obtain your distance from the exchange.


This can be a very handy test to perform so you can an idea of what sort of speed your broadband should be.

A good test to do before you buy a house in a remote area!!!

To do this dial the BT telephone engineer line test number 17070,

If the number doesn’t work for you and all you  get is ”There is no CLI detected for this circuit”.

This means you have Caller ID blocked on your line. To get around this dial 1470 17070 instead .

select option 3 (fast test) then option 1 (to say you are authorised). Then press option 2 (ring back test) and replace the handset.

After about 10 seconds you will be called back and one of the pieces of information returned will be the distance from the exchange (in kilometres). BT telephone engineers normally repeat this test 3 times and take an average.

The results itself are calculated by sending a low amplitude high frequency signal down your line and listening to the farthest reflection (at your house) – therefore they are likely to vary by 100 meters or so.

How to find the length of your BT telephone line

How to find the length of your BT telephone line

How to test your telephone line

If you’re having problems with your telphone line, whether a noisy line or
you have no dial tone, use the following quick tests to help identify
where your problem lies.

If a BT Openreach Telephone engineer is scheduled for a visit and
your problem is deemed to be related to your own equipment or internal wiring, charges in excess of £120 for the visit and £70 an hour may be applied by your service provider.

In the very first instance of experiencing problems with your line, check the following basics with your own telephone equipment

Are any of your telephones off the hook?
Look at the telephone cables and any power cables – are they securely plugged in?
Check Microfilters are installed into the telephone socket where required.
For cordless telephones, please make sure the battery is charged.
If all of the above checks test ok, unplug the telephone that you are having problems with and try another telephone in the same telephone socket. If your problem goes away, then your telephone is at fault. If your problem persists, continue to step 3.
Connect your telephone into the MASTER TEST SOCKET. If possible, use a corded telephone as opposed to a cordless base station. When testing at the TEST socket, all other telephone equipment should be removed from the telephone socket – including Microfilters, doublers any other extension wiring.Your Test socket can be found behind the Master Telephone Socket Faceplate. This telephone socket is the point where your telephone line enters from outside into your property. In most residential dwellings, this is often towards the front of your property. The latest Master sockets will have either the BT Piper logo or Openreach logo on the top left corner.
Remove the 2 small screws on the Master Telephone Socket Faceplate, The master telephone socket may have a BT logo on the top hand corner of the faceplate and will be the only socket with the TEST socket behind.
Carefully take out the bottom half of faceplate.
On the right hand side beneath the face plate you should now be able to see the TEST telephone socket.
Plug your telephone into the TEST socket.
If after testing from your TEST socket you telephone now works, you may have a problem with your internal wiring.

If after carrying out the above tests you are still experiencing problems, please contact me on 01277 287 077 – 07882 691 192 and I will be happy to assist you further.