Due to an issue with one of our macs I had to completely wipe the hard drive of the mac and re-install.
Cue the issues with re-installing, for whatever reason it would not accept the apple id and password to re-install. Solution? Time Machine to a fresh portable drive of the new macbook I'd just built and then went over the old macbook with the new Time Machine image. Result! (and as an added bonus meant it didn't have to wait several hours downloading the company data onto the old machine).