In reply to a post by GonePostal:

Presumably your mum has no need for FTTP speeds so worth looking at a provider like EE over FTTC for both broadband and phone which will retain the landline number.

If FTTP is available to order at the property, then FTTC and FTTP (at a basic speed like 80/20) will likely be the same price.

In both cases, the voice service will be delivered in exactly the same way: as digital voice over the broadband, where the handset plugs into the router. You have been unable to order or migrate analogue voice (PSTN) services since Sep 2023.

Furthermore, the FTTP service will be more reliable - not relying on powered street cabinets or high attenuation copper affected by temperature, bad joints, water ingress etc.

In reply to a post by candlerb:

If FTTP is available to order at the property, then FTTC and FTTP (at a basic speed like 80/20) will likely be the same price.

Only if the FTTP is from Openreach. The OP said Virgin Media, and it may be VM over the nexfibre network.

Virgin Media do voice services, via the router (“hub”) in both nexfibre, and real virgin areas. If you’ve not chatted to them double check as I know people in coax, RFoG, and nexfibre FTTP areas all with traditional phone line via the Virgin Media hub.

I personally choice NOT to pay for home telephone from the ISP.

In reply to a post by jchamier:

In reply to a post by candlerb:

If FTTP is available to order at the property, then FTTC and FTTP (at a basic speed like 80/20) will likely be the same price.

Only if the FTTP is from Openreach. The OP said Virgin Media, and it may be VM over the nexfibre network.

True. The existing service is 60M FTTC over the Openreach network, but they are paying way too much at over £50 per month; it will be easy to bring that down.

The alternative VM Fibre has £24 per month initial price, but that will likely double or triple at the end of the initial contract period unless you threaten to disconnect. So it partly depends how much they're prepared to jump through those hoops.

I haven’t been able to look though all the answers but I can tell you that in the last week I have had my old landline number ported to a VoIP service (successfully and quickly). For context I already have a (non landline) internet service and was ‘pushed’ to look at VoIP because my landline supplier (PlusNet) are doing the “Digital Switch” and could not supply what I needed.
The company I used is Premitel Connections based in Haddington, East Lothian but I see no reason why you couldn’t get the same service anywhere in the UK. I got an ATA (analogue telephone adapter) so we (well my wife) has something familiar (our existing DECT phones). I know Premitel can & do advise and the main chap Stephen K is responsive & helpful. The switch took less than 2 weeks and it has been seamless - I’m 72 and hope to last to the grand old age of your Mum - I know I would have done the same for my parents had they lasted this long
Happy to answer specific questions if you have them