A high percentage of people moving in to a new home do not replace the locks even though they are often unaware who had a set of keys previously. Do contractors, cleaners, previous owners or tenants have a key or a set of keys to your home? I also visit many customers that don’t have keys to use there own mortice locks and they rely on a Yale type night latch for security. If the door was forced or slipped open with a card by thieves and the mortice lock wasn’t locked at the time, the home insurance company may not pay your claim.