You’ll have a small network termination point on the wall that may look similar to this.
In which case we’d recommend doing these checks.
Check that you
have power to your equipment (phone, modem, etc.) and that it is switched on.
The Openreach equipment will work using the battery back-up for a time after
any power cut, so that you can make emergency phone calls, but your service
provider’s and your equipment may not.
phones/handsets aren't faulty – test each phone by unplugging them and
re-connecting them one at a time – making sure to check the line each time.
Check any equipment that's connected to your telephone line in the same way – this may include routers, televisions, set top boxes, modem, faxes, alarms and auto dialers (care systems).
broadband equipment by turning the power off and on again, allowing sufficient
time for your equipment to power up.
Make sure all
the cables are correctly connected and haven’t become loose.
If using Wi-Fi,
check your connection is working correctly. Do you have another device you can
test this from?
Test with a
different broadband router if you have one available.
contacting your service provider, it may be helpful to have an alternative
phone available when they are running tests.
If the problem continues, then you should contact your service provider. Your most recent telephone bill will have the details of your service provider and how to contact them.