Hi mrglwatson,
That's no problem at all.
When it came to switching over, we would install a broadband hub to allow him to access the phoneline but he would not be able to use broadband unless he takes out a broadband package. He would also need to book an engineer for the switch to take affect so as soon as he is notified, he will need to contact us so we can get the visit booked in for him.
Hope that helps to explain things 🙂
Thanks,