Mortice locks are possibly the most, if not one of the most common types of door locks. There are two variations and they are Mortice Sashlocks and Mortice Deadlocks.
A combination of a mortice lock and a handle-operated latch mechanism make up a mortice sashlock. With this pairing, you are able to open the door without the need of a key however to lock it securely when you leave the house you must use a key. There are varying levels of security with sashlocks, level 3 is mid-level security and level 5 is the highest security level. When purchasing a mortice lock, you must ensure it complies with British Standard BS3621 and the British Standard kitemark.
Mortice Deadlocks are frequently used on front doors where additionally security is needed. They are often used in conjunction with a nightlatch and a key is needed to both open the door, and to lock the door.