Moving House

I am planning to move house

Currently have BT line and BT Internet

The new house does not have an active BT line so I will need it connected/activated

Should I just do a straight transfer of my BT account and set up the new line (It is in a different area code) or should I cancel my existing line and start a new account?

I want to cancel the BT broadband and get O2 at the new line - as it will be a different line do I need a MAC code?
When I tell BT I am cancelling the existing net will they cut it off immediately or will it keep working til the end of the month?

No MAC needed. If you already own the property you can get a BT line installed/activated whenever you like but it will have a new number.

If it all has to be done on moving day then let BT know to terminate both accounts (line and BB so it will be two calls to do that) on the day and arrange for the new BT line to be installed/activated on your current phone account. You should do this in advance as there will be notice periods required for both. Make sure the old BB is terminated and not transferred - no need to give them the new address even.You'll have to contact O2 after the line is installed in the new property.

Might be worth a look at this thread.