Night Latch vs Deadlock: What's the Difference and Which Do You Need?

If you have a traditional wooden front door, you've probably got a night latch (the lock you pull shut behind you) and possibly a deadlock (the one you turn with a key). But what's the difference, and do you really need both?

A night latch — commonly called a 'Yale lock' after the most popular brand — is a spring-loaded lock that automatically locks when you close the door. It's convenient because you don't need a key to lock it from outside (though you do need one to open it). The latch can usually be set to 'deadlock' mode using a snib on the inside, which prevents the latch from being pushed back.

A deadlock — specifically a mortice deadlock — is a key-operated lock that's embedded within the door itself. When you turn the key, a solid steel bolt extends into the door frame. Unlike a night latch, a deadlock can't be opened without the key (from either side), and the bolt can't be pushed back or forced without significant effort.

For proper security — and to meet home insurance requirements — your wooden front door should have both: a night latch for everyday convenience and a BS3621 five-lever mortice deadlock for security. The night latch alone is not sufficient because the latch can potentially be bypassed (by slipping a credit card or similar flexible tool between the door and frame), and most night latches don't meet BS3621 standards.

The deadlock provides the primary security, while the night latch adds convenience and an additional locking point. Together, they provide comprehensive protection that meets insurance requirements.

If your wooden door only has a night latch, or if your deadlock doesn't have the BS3621 kitemark, call Oldham Locksmiths on 07949 139 475 to arrange a deadlock fitting or upgrade.