Many are not aware that all households will be moved to Digital Voice only. The old PSTN will be switched off in December 2025. This means that residents with a land line will be moved to a digital phone system. This is relatively straightforward for homes with broadband connections and your broadband provider should provide free replacement phones. However, for land line users only equipment will need to be installed to provide a specially dedicated broadband connection for the digital phone.
There is a good article on Which that explains the Digital Voice and Landline Switch-off.
For most users, the change over should be straightforward. However, the digital phone system is not perfect for complicated set ups in larger properties. The digital phones link directly to the broadband hub. So may not have the range for the whole house. You may need Digital Voice Adapters that pair into the hub and then can be moved to a more convenient location and plugged into a normal electric socket. An existing non-digital phone is plugged into the adapter. As long as the adapter is within range of the hub, you will be able to use a standard phone as before. For further coverage BT DECT repeaters are available from outlets like Curry’s. These extend the range of BT DECT-based phones. Digital phones can be used together with standard phones using the setup of Digital Adapters and hub.
Our experience is that BT agents are not fully up-to-speed with more complicated setups but it now seems that we have a workable solution with both wifi and phone coverage throughout our house.
Hope this explains a little about the switch over. Something we were not aware of until we upgraded our wifi and took the offer of free digital phones.