This is the main form of defence against door attacks and, as a result, high security mortice locks are a standard requirement for home contents insurance. The length of bolt that is thrown into the door frame is directly related to the level of protection that you will obtain. If you are burgled and it is later found that you did not have an appropriate lock on your door, then your insurance company can refuse to pay your claim.

Mortice locks with a lower security rating can be put on interior doors such as the bathroom door.