Roger Mills wrote:

can anyone suggest the best way of making calls from the flat without
actually being there?

A VoIP adapter (e.g SPA3102) with an ethernet connection to the ADSL
router, and PSTN connection to the phone line, you could then make a
VoIP call "in" to the ATA which it is configured to dial "out" via the PSTN

I use 0330 1234 151 (BT residential faults service) for my mandatory two
calls, the email from BT to say the bill is ready is the reminder to
make the calls, regardless of whether I can remember making other calls
that month or not.