Door Lock Installed Backwards or Upside Down? How to Fix It

A lock installed backwards usually means the latch bevel faces the wrong way, so the door won’t close by itself, or the deadbolt was put in upside down so the thumb-turn and key work in odd directions. Both are usually fixed by taking the lock apart and turning the latch or cylinder around.

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Signs your lock is backwards

• The door won’t click shut. The sloped side of the latch should face the direction the door closes. If the flat side hits the strike first, the door bounces open.
• The keyhole is upside down compared with the other locks in the house. Many locks work either way, but some are designed for one direction.
• The deadbolt turns the “wrong” way or the thumb-turn sits sideways when it’s locked.
• The lever handle points the wrong way or springs down crooked.
• The key or code side is inside and the thumb-turn is outside. This is a security problem and needs fixing right away.

Fix a backwards latch

1. Remove the knob or lever (usually two screws on the inside, or a release slot).
2. Unscrew the latch plate on the door edge and slide the latch out.
3. Turn the latch so the slope faces the strike side when the door closes.
4. Slide it back in, making sure the latch’s holes line up with the lock’s spindle.
5. Reinstall the knob or lever and test with the door open first, then closed.

Upside-down deadbolt

Many deadbolts work in either orientation, but the bolt and the cylinder have a right way up. When the deadbolt is upside down, it may still lock but feel stiff, or the thumb-turn sits at an odd angle. To fix it, remove the interior thumb-turn, pull the cylinder, and reinstall it the correct way with the bolt in the retracted position. Check the instructions for your brand because the tailpiece needs to line up with the bolt. If your deadbolt is new, our deadbolt install guide walks through the order of parts.

Lever handles that point the wrong way

Many levers are “reversible” or “handed.” If a lever points toward the hinge side instead of away from it, the lever often needs to be flipped using a release or a small part inside. The steps vary by brand, so check the instructions.

Test before you’re done

• Door closes and latches on its own with a gentle push
• Deadbolt throws fully with the door closed
• Key or keypad on the outside; thumb-turn on the inside
• No rubbing or grinding when locking

If the door closes but won’t latch after the fix, go to door won’t latch.