Seems a bit pointless delaying them switching you to Digital Voice.
PSTN is being turned off in 2025 but BT want all their customers on to Digital Voice
before then.
A burglar alarm might delay the process by a year, but it's going to happen.
It's already not an option for new customers.
Rather than contacting BT to delay a switch to Digital Voice, why not call the alarm company and get them to make whatever changes are necessary to make the alarm work without an analogue phone line.
There are a number of solutions that can be retro fitted to existing alarms.
Seems pointless making effort and spending time delaying what's going to happen anyway rather than using that time to get an alternative solution in place.
From what I understand with FTTP you cannot use the digital voice service if there is a power outage because there is no back up battery supplied
A small UPS fixes that.
An ISP can provide these for free to vunerable customers with no mobile signal.
Some providers will choose to simply stop providing landlines altogether when PSTN goes rather than develop a VOIP alternative.
Talktalk have already done this with FTTP where it's data only. There's no way to get a landline on their full fibre.
They are also rumoured to be launching broadband only FTTC packages in the near future (SOGEA).