I'm moving House but the Renters Act has kind of messed it up a bit. I take over the new contract in the middle of next month, but won't be fully moved until the end of the month. As I work from home, I'll need to have connection during the overlap at the old (current) property, but need to replace the house owner on the day he moves out or they will terminate the line, meaning it's a new installation. Can I overlap the contracts for ten days?
I presume you are going to use BT House Move as per this link.
As far as I am aware and I could be wrong you won't be able to have a connection at both addresses at the same time with the one broadband account.
If you want a connection at the new address on a date prior to you ceasing the connection at the old address you will need to take out a new broadband account at the new address and have it running in unison with the contract at the old address.
When you finally move to the new address you will then need to cease the broadband contract for that address which may result in you paying early cancellation fees for that broadband account if you are still in a fixed term contract.
Having said that you would be best to call BT Home Move Team ob 0800.783.0235 and seek their advice as to what is and is not possible.
Terminating the line at the new address wouldn't absoluteley mean a new installation. If it's FTTC it would just be re-activated without an engineer visit