Removing phone sockets

[GetUpStandUp4]

Got a plasterer coming tomorrow to skim the walls of living room and we don't want to keep the phone socket. I opened the cover and there's a back wire leading through external wwall and another small white wire going underneath the box and under carpet. can we remove ourselves and how?

There's another socket behind the TV next to the virgin cables. don't mind keeping that one

If you remove the connection to the outside the others in the house won't work (if I've understood you correctly). The wire going under the carpet likely feeds the connection you want to keep.

we have virgin so we don't need the old bt wires. pretty sure it's not the master box

I'd keep it with some kind of closed off plate. You never know, you might need it one day.