House moves with most ISPs start a new minimum term (contract). Plusnet does, as per their T & Cs, Section 2 on this page
, last updated March 2014.
Re the phone question, if there is still a phone service there is it still in use by the current residents? Does it also happen to have broadband on it?
Re the MAC, that has to be a nonsense. You can't get a MAC for a broadband service belonging to someone else - that's assuming there is a broadband service on it anyway, and that it's one where MACs are available.
Edited by RobertoS (Fri 10-Apr-15 22:27:52)