David Hansen wrote:

cable and use that for the extensions. If I was putting a telephone
socket beside the ADSL socket this needs two and a half pairs, say
three pairs. If my telephone cable was only two pair then I might
use Cat 5, simply for the extra pairs. Alternatively three pair
telephone cable should be fine. Avoid sharp bends and don't staple
the cable.

Do you mean all these pairs are needed just for the phone, or something
else? The UK phone system uses 3 wires, with a lot of equipment working
on only 2 wires. If desired its elementary to run a 2 wire system and
add a capacitor at the end to give a standard 3 wire outlet.

NT