I think a problem with forums like this is that everyone sees their own suggestions, and doesn't realise that the aggregation of those from several people appear to be contradictory.
The comment you quoted there, as well as appearing to contradict at least one other person here, also goes against my previous experience of having VoIP provided over my broadband by someone who was not my ISP, and also seems to contradict what my ISP said this morning, which is that I can keep my broadband with them and my voice separately from whoever I want (including them, but not necessarily them).
Here is what my ISP said:
---8<---
No, you don't have to have your voice and broadband from the same provider.
After the PSTN switch off your phone number is no longer tied to a physical phone line. Voice services will be VoIP (Voice over IP), you will be able to port your number to any VoIP provider you like and take your broadband from any broadband provider you like, they don't have to be the same provider.
Your ISP is right for some voip services but digital voice from BT needs broadband & you can only have 1 broadband on a line. TBH it'll probably save you money too as you'll br paying for standard line rental with BT too
Any internal extensions are the responsibility of the customer. If you read the FAQ you will see that is possible to re-connect the extensions, to the new connection point, but that would need to be done by the customer, or someone competent.
That may prove difficult with a third party VOIP provider.
Thanks, Keith.
Does that mean that after my mother gets notified she is going to need to find a local tradesman to do this for her? BT will just break her existing provision and not put it right. That's, um, poor.
You mention a FAQ. Where can I find that? I have hunted over the web for something that answers these questions, but can't find anything, and BT refuse to tell us anything until she has been given the two weeks' notice.
To try and clarify, you were previously able to pay for line rental and telephony from one supplier and broadband from another.
Going forward, all broadband contracts include line rental but may or may not include telephony service.
As far as BT is concerned, you can have broadband with or without their proprietary VoIP system (Digital Voice). If taking broadband without DV, a third party VoIP service can be taken. Other ISPs may or may not provide their own voice service and third party VoIP providers may also be used.
As far as existing sockets are concerned, it depends on how the existing wiring is configured. It is a relatively straightforward operation to configure existing wiring to be utilised but will be your responsibility to do so.
FAQ https://community.bt.com/t5/Home-phone-including-Digital/Digital-Voice-FAQs/td-p/2207485
This post as well as off topic is also going over the same ground , if @blackprince has BT telephony with another ISP providing broadband ( utilising SMPF ) then when all BT telephone is via DV ( because the PSTN network has been retired ) to stay with BT for telephony it would have to be via DV , and that will require the customer to also have BT Broadband or no broadband at all over Openreach ,, and in the background, free to the customer, they will connect to BT Broadband , but a low bandwidth version only capable of telephony, but because it is broadband, it means no other broadband can be on the same ‘line’ .
If they prefer to stay with the current broadband provider they have to leave BT , this broadband provider may offer their own IP telephony service , or the customer can use a traditional VoIP provider, or even both , but in that case it would have nothing to do with BT and by extension, this BT customer forum.