I have a 1960s house with wooden doors. They have yale lock at the top and then a chubb lock in the middle, then they have manual bolts at the bottom. If I don't have a five lever mortice deadlock its pushing my insurance premiums up by about £250. How do I know whether I have? I can't see any BS kite marks but then the doors are quite old.
A mortice deadlock is the sort with a keyhole on both sides, rather than some sort of latch. You need a key to open it from either side of the door. I think if you look at the key it should have 5 notches, but I'm not sure.
Check your insurance details though - we had an old Victorian door that was too thin to house a mortice deadlock, so we were allowed to use deadbolts top and bottom instead.