Lost House Keys? What to Do Next, and When to Rekey

If you have lost your house keys, spend the first few hours retracing your steps and calling the places you went. If the keys do not turn up, rekey every lock they opened so the lost key stops working. Do it the same day if anything on the ring could lead someone to your door: an address tag, a wallet lost with the keys, or a car key whose registration sits in the glove box. Rekeying keeps the locks you have and changes the pins inside them, so you do not need new hardware just because a key went missing.

First, find out whether they are lost or just misplaced

Lost keys often turn up somewhere obvious once you look calmly.

The door itself. Check the outside of every door you used. Keys left hanging in a lock are more common than anyone admits.
Pockets and bags. Every coat worn that week, the gym bag, the tote, the stroller basket.
The car. Under the seats, in the door pockets, in the gap beside the console.
Work. Your desk, the coat rack, the bathroom shelf.
Anywhere you paid for something. Call the shop, the café, the dry cleaner.
Children's bags. If a teenager borrowed the spare, start there.

Commuters have a longer list. Between the house, the car, the station lot and the train, a key ring has plenty of places to fall. Metro-North runs a lost and found, so if you rode the train that day, report the keys there and describe the ring.

While you look, keep a spare with you or with someone in the house, and lock the doors you can.

Work out what was on the ring

What was on the ring decides how fast you need to move.

Anything with your address. A tag, a fob from a building, a letter in the same bag. Rekey the same day.
Your wallet. Your license shows your address. Treat it the same as an address tag.
A car key or fob. Whoever has it may also have your car, and the registration in the glove box shows your address. If the car key is gone for good, see our car key replacement service as well.
A garage remote or a building fob. These open doors without a key at all. Deal with them alongside the locks (more below).
Office keys. Tell your manager or the building. Those locks are not yours to decide on.
Nothing identifying. A plain ring of keys dropped in a car park is lower risk, but it is still a key that fits your door. Rekey once you are sure it is gone.

Rekey the locks the lost key opened

Rekeying means taking the cylinder out, swapping the pins for a new set, and cutting new keys to match. Your deadbolts, knobs and handles stay on the door. Every copy of the old key stops working, including the one you lost. Our lock rekeying service covers house locks, and if any lock is also worn or damaged, our guide to rekeying versus replacing explains when a new lock is the better answer.

Make a list before you call:

Every exterior door the lost key opened: front, back, side, the door from the garage into the house.
Whether the knob lock and the deadbolt on each door took the same key. Count cylinders, not doors.
Any shed, gate or basement padlock on the same key.
Any lock you want on the same key as the others. Losing a key is a good moment to put every door on one key, as long as the locks share a keyway.

Then decide who gets a new key, and how many to cut. Fewer copies in circulation means fewer to lose next time.

The garage, the remotes and the codes

A lost key is not always the only way in.

Garage door remotes. Most openers can erase every stored remote with the learn button on the motor unit, after which you re-pair the remotes you still have. Check the manual for your model.
Keypads. If the lost ring had the garage keypad code written on a tag, change the code.
Smart locks. Delete any code or app user you no longer need, and if the lock has a physical backup key on the lost ring, rekey that cylinder too.
Hidden spares. If a spare lives under the mat or in a planter, someone who finds your keys may look there as well. Move it, or give it to a neighbour.

The door-by-door walk in our post on rekeying a house you just bought works just as well after a lost key. It covers side doors, garage entries and the codes people forget.

Larchmont commuters and the morning rush

In Larchmont, a lot of key rings spend the day split between a house, a car at the station and a desk somewhere along the New Haven Line. That is a lot of ground for one ring to cover. A typical call looks like this: a commuter reaches the platform, or the front door, and finds the pocket empty.

Two of our three technicians live in Larchmont, so the village is home ground, from Larchmont Manor to the streets around Flint Park. The Larchmont locksmith page has more on lock work in the village, and the same rekey applies anywhere in the twelve towns we cover.

A few habits help:

Keep the house key and the car key on rings that come apart, so losing one does not mean losing both.
Never put your address on a key tag. A phone number for return is enough.
Leave a spare with a neighbour or a relative nearby, not hidden outside.

If you are locked out right now

Get inside first and deal with the locks second. Try every other door, call anyone else who lives there, and ask the neighbour who holds your spare. If none of that works, our emergency lockout service runs any hour, and average response is about 25 minutes. If your wallet went missing with the keys, say so on the phone, and have something else that shows the house is yours, such as a utility bill or a lease on your phone. Once you are in, ask whether the rekey can be done in the same visit.

Frequently asked questions

Do I need to change my locks if I lost my keys?

Usually you need new keys, not new locks. Rekeying makes the lost key useless and keeps your hardware. Replace a lock only if it is worn, damaged or too weak for the door.

Can a locksmith rekey a lock without the key?

Usually, yes. It takes more work, because the cylinder has to be opened or removed without a working key first. Tell the locksmith on the phone that you have no key, so they come prepared.

How soon should I rekey after losing my keys?

The same day if anything on the ring shows your address, or if your wallet went with it. Otherwise, once you have retraced your steps and are sure the keys are gone. Waiting weeks leaves a working key out there for longer than it needs to be.

Do I need a new garage door opener?

Usually not. Most openers can erase their stored remotes, after which you pair the ones you still have. Check your opener's manual, and change any keypad code that was written down on the lost ring.

If your keys are gone and you want the locks rekeyed, call Larchmont Locksmith NY at (914) 255-6611 any hour.