Thanks for you response jpeg1 but I still can't resolve it.
Yes, we both have broadband/TV in our home homes. ie totally separate accounts. My father isn't good with IT so I set his package up (some months ago) using my email (gmail) and his account number etc. He does have his own email address - wish I'd used that now!!
Of course, now when I log in I can only see his account which is what I'd expect. No idea where mine is.
I've tried setting up a new account using my account number etc and a different email address (outlook) but I get a message telling me that account already exists and sends an email to my original (gmail) email address to log in.
I'm going around in circles