If the apartment is OR FTTP only ( no copper pair service ) then obviously only Telcos that offer service over that FTTP network will be able to offer any service, those company’s products and prices are not discussed on this BT Consumer forum so you would have to do your own research ( for example, some company’s only offer broadband , with no telephony , some don’t offer FTTP products at all, and only copper pair based products )
As already stated , slower speed profiles are available on BT FTTP , at the same price as those on copper pair delivery , so 40,55,80Mb are available on FTTP , you don’t have to take hyper fast speeds if you are on FTTP .
Comparsion / switching sites have generally ( in the T&C’s ) things along the lines of ‘ not all products are available in all locations’ , so how accurate they are , is nothing really to do with BT .
If you , or your mother are considering switching provider , and want to move the BT DV telephony number to another provider , there is no BT imposed barrier to why a new provider couldn’t import that number , number portability is a requirement the regulator insists on , but confirmation that it can be provided, is a question for the new provider , and should the outcome be problematic ( in other words the number is lost ) that would be something for the new company to resolve, and how successful they will be is again not really a question for BT.
Some people port phone numbers to VoIP providers , that way the number is separate from any broadband provider , but obviously a broadband connection is needed to access it , should that be considered, porting the number to VoIP will cease the broadband, obviously a new company could reinstate service with or without a telephony service ( depending on what provider is selected ) but would currently result in a period without broadband service, but obviously there is no reason why switching broadband service provider and porting the phone number cannot be done , but it’s the responsibility of the gaining provider not the losing one , is it a risk worth taking , only you and your mum can answer that.
