Rekey or Replace the Locks When You Move In and Can't Count the Keys

When you move in and can't account for the old keys, either rekeying or replacing the locks will stop those copies from working, because the lock no longer responds to keys made for its old setting. Rekeying resets the inside of the lock you already have. Replacing swaps the hardware. Choose by the lock's condition and whether you want something different from it, such as a smart lock or a higher-security lock.

Why the number of old keys stops mattering

A key opens a lock because its cuts push small pins inside the cylinder, the part with the keyhole, to the right heights. Change those pins and any key cut for the old setting stops turning the lock, whether two copies are out there or twenty.

That takes the pressure off a move-in. You don't need to learn who kept a spare or match the unlabeled keys in the envelope to doors. Once each lock answers to a new key, the count stops being your problem, and rekeying and replacing both get you there.

Rekeying keeps the lock you already have

Rekeying leaves the lock, its handle, and the plate around the keyhole on the door. The pins inside the cylinder are changed to match a new key, and new keys are cut. From the outside, nothing looks different, and you lock and unlock the door the same way as before.

Rekeying fits when the locks are sound. The key slides in without force, turns without a catch, and the deadbolt runs fully out and back. If you like the hardware and it works smoothly, resetting what it answers to solves the key problem without changing how the door looks or feels.

The limit is that rekeying fixes the key, not the lock. A worn cylinder or a bolt that drags will still do so afterward.

Replacing swaps the hardware itself

Replacing takes the old lock off and installs a new one with its own keys. The new cylinder was never set to the old keys, so replacement ends old-key access just as rekeying does.

Replacement is the better fit when the hardware is the trouble: a key you have to jiggle, a lock that sticks, a bolt that stops short, loose or damaged hardware, or a mismatched set of locks from different eras. It also makes sense when you want the door to work differently, such as moving to a higher-security lock or a smart lock that opens with a code.

If the latch no longer lines up with the strike plate, the metal plate on the frame that the bolt slides into, a new lock alone won't fix that. The door or frame needs attention too.

How do you tell which one a door needs?

You can judge most of this without taking anything apart. Stand at each exterior door with the keys you were given and go through these points.

• The key should slide in and turn smoothly. Grit, a hitch partway through the turn, or needing to jiggle it suggests wear.
• With the door open, the deadbolt should extend fully and pull back cleanly. If it turns easily with the door open but hard with the door closed, the bolt is rubbing on the frame.
• Movement you can feel in the handle or the ring around the keyhole points to loose or worn hardware.
• A patchwork of different lock types may not all take the same key, which matters if you want one key for every outside door.
• If you have wanted keypad entry or a sturdier lock, replacement handles the old keys and the upgrade together.

A door that passes these checks, with hardware you're happy with, is a good rekey candidate. One that fails a check, or that you want to change, leans toward replacement. The answer can differ from one door to the next in the same home.

Getting ready, and what to do with the old keys

A short hand-over list makes the first call easier:

• How many exterior doors need attention, including back or side doors
• What lock is on each, such as a knob, lever, deadbolt, or a combination
• Your notes from the door checks, door by door
• How many new keys you want, and whether one key should open every exterior door

NoMad Locksmith & Security schedules non-emergency lock work by appointment. To talk through rekeying or replacing the locks at a home in NoMad or elsewhere in Manhattan, call (917) 337-9703.

After the change, test every new key in its door before the old keys go anywhere. Then discard the old keys or keep them well apart so they never get mixed back in. Decide who gets a copy of the new keys and keep track, so you know the count from the start.

Frequently asked questions

Do I need to find the old keys before the locks are rekeyed?

No. Rekeying changes what the lock cylinder answers to, so every old key stops turning it whether anyone ever finds that key or not. The keys you did receive are still worth setting aside, with a note of which ones open which doors, since trying them shows whether each lock works normally before the change.

Can all the doors be set to work with one key?

Often, if the locks share a compatible keyway, the shaped slot the key enters. Locks from different makers or eras may not take the same key. In that case, replacing one or more of them with matching hardware is what makes a single key possible. Mention that goal when you arrange the lock work.

Should I handle the locks before or after unpacking?

Handle the locks before unpacking, or as early in the move as you can. Old copies keep working until the locks change, so dealing with them first shortens the time someone else's key still opens the door. Doorways are also easier to reach and test before boxes pile up. If movers need access, plan the new keys around that.