Deadlatch vs Deadlock: What's the Difference?

Short answer: a deadlatch locks automatically when the door closes and can't be slipped open with a card. A deadlock has to be locked deliberately, usually with a key, and once locked it can't be opened without the key or a turn knob. In Victoria, rental providers must make sure every external door has a working deadlatch with at least one cylinder.

What is a deadlatch?

A deadlatch has a spring-loaded latch that clicks into the door frame when you close the door, so the door locks itself. What makes it a "dead" latch is a small extra plunger beside the latch. When the door is shut, that plunger is held in, and it stops the latch being pushed back with a card or a thin tool (a trick called "slipping" or "loiding").

Key points:

• Locks automatically when the door closes, so it's easy to lock yourself out.
• Opened from inside with a handle or knob, usually without a key.
• Many deadlatches also have a deadlocking function you can set with the key, so the inside handle won't open it either.

What is a deadlock?

A deadlock has a solid bolt that you throw into the frame with a key (or a turn knob on the inside). It doesn't lock itself when the door closes. Once it's locked, the bolt can't be pushed back, and a "double cylinder" deadlock needs a key on both sides.

Key points:

• Must be locked on purpose, so you can't lock yourself out just by closing the door.
• Stronger bolt, usually harder to force.
• Needs a key from inside on double cylinder types, which matters for fire safety (see below).

Side by side

	Deadlatch	Deadlock
Locks automatically when the door closes	Yes	No
Resists card slipping	Yes	Yes
Can be opened from inside without a key	Usually	Not always
Typical use	Front doors, rentals	Extra security on front, back and side doors
Risk of locking yourself out	Higher	Lower

Which is more secure?

A good deadlock usually offers stronger resistance to forcing, because of the solid bolt. A deadlatch has the advantage that the door is always locked when it's closed. Many homes use both: a deadlatch for everyday locking and a deadlock for when nobody is home or at night.

The fire safety trade-off

If a door is deadlocked and needs a key on the inside, you can't get out quickly in a fire unless the key is within reach. If you deadlock doors while you're home, keep the key in the lock or close by, and make sure everyone in the house knows where it is.

What Victorian rentals need

Consumer Affairs Victoria says a rental provider must make sure each external door of a rental property has a working deadlatch with at least one cylinder. External doors that can't take a deadlatch must have another locking device, and windows need latches that secure them against entry from outside (Consumer Affairs Victoria: locks and security). These are part of the rental minimum standards.

If you're a rental provider or property manager on the Peninsula, see lock changes and rekeying.