Usually there is a box on the outside of the house where the cable - for example - comes out of the ground. There is then usually a cable from that box in through the wall to the master socket. If you can find the outside box, I'd be inclined to remove the wiring your side of that box. That leaves the service intact for other future users.
+1
The outside box will be easily opened, or may even just be a plastic cover. Disconnect the cable going from it into the house. It will either be a screw or crimp connection. Dead easy to snip the cable going into the house or remove it from the connector. Everybody will be happy. If BT do ever need to resupply the property, then its an easy job for them and not worth their coming out to remove their old cable and interior box.
Too many doomsayers sometimes about BT . They would only get uptight if some idiot connected their cable to the household mains!
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