First: how worried should you be?
Ask what the keys were with. A bare key ring dropped at the park is one thing; nobody knows which door it opens. Keys lost with your wallet, your bag, your car or anything with your address on it are another, because now the finder knows where the lock is. Keys stolen in a break-in or taken by someone you know are the most urgent of all. In the last two cases, treat it as a same-day job.
Rekey or replace?
A rekey changes the pins inside each lock so the old keys no longer work and a new key does. The locks stay on the door, which is why it costs a fraction of new hardware and takes minutes per lock. It is the right answer whenever the locks themselves are in good condition.
Replace a lock when it is worn, loose or stiff, when it is a cheap knob with no deadbolt behind it, or when it is a different brand from the rest of the house and will never share its key. Most houses end up with a mix: rekey the good locks, replace the one or two that were never good.
The doors people forget
- The door from the garage into the house. It is an exterior door in every way that matters, and often the easiest one to reach unseen.
- The side gate, if its lock took the same key.
- The mailbox. A mailbox key lost with your house keys gives someone your post, which is how identity theft starts. Our mailbox lock page covers cluster boxes and individual ones.
- The garage door opener, if it was on the key ring or in a lost car: reprogram or clear it, because it opens the house too.
- Any smart lock's backup key and codes, if a code was written down with the keys.
What it takes
We need to know you live there: an ID with the address or a lease. If you are locked out as well, we open a door first. Then we rekey each exterior lock to one new key and cut as many copies as you want on the spot. A typical house with a front door, a back door, a garage entry and a side gate is done well within an hour. If the lost keys included a car key, that is a separate job, covered in our lost car key guide.
Renting?
Tell your landlord or property manager first. Most leases say who pays and who arranges the work when a tenant loses keys, and many landlords want their own locksmith or a copy of the new key. If you are a landlord reading this, our guide for California landlords covers locks between tenants.
Questions people ask
Is rekeying as secure as new locks?
For lost keys, yes. The old keys stop working completely. New locks only add security if the new locks are better than the old ones, such as a higher grade or a restricted keyway.
Can all my doors end up on one key?
Usually. Locks of the same brand are rekeyed to the same key, and a lock of a different brand gets a matching cylinder.
How quickly should I do it?
The same day if the keys were lost with anything showing your address or were stolen. If a plain key ring was lost with nothing to identify it, within the week is reasonable.
Do I need to change the mailbox lock too?
If its key was on the lost ring, yes. Your mail carries bank statements and documents, and it is the lock people most often forget.