- Rekey when your locks work well and you only need old keys to stop working.
- Replace locks that are worn, damaged, low quality, or when you want a stronger or keyless lock.
- Rekeying changes the pins inside the cylinder, not the lock's strength or resistance to force.
- Rekeying is usually cheaper; mixing both, rekeying good locks and replacing weak ones, often gives the best value.
If your locks work well and you just need old keys to stop working, rekeying is usually enough. It is typically the cheaper, faster option. If your locks are worn, damaged, low quality, or you want a different kind of lock (stronger, keypad, or a new style), replace them.
The key question is simple: is the problem who has a key, or is the problem the lock itself? Rekeying fixes the first. Replacing fixes both.
What rekeying actually does inside the lock
Most home and office door locks in the US are pin tumbler locks. Inside the cylinder is a rotating part called the plug. Small spring-loaded pins sit in a row of holes that pass through the plug and the housing around it.
Each hole holds two main pins:
- Key pins (bottom pins) touch the key. They come in different lengths.
- Driver pins (top pins) sit above them, pushed down by small springs.
When no key is in the lock, the driver pins cross the gap between the plug and the housing. That gap is called the shear line. With pins blocking it, the plug can’t turn.
When you insert the right key, each cut on the key lifts its key pin to exactly the right height. Every pin pair splits right at the shear line, and the plug turns.
To rekey, our technician:
- Removes the cylinder from the door (or works on it in place, depending on the lock).
- Slides the plug out of the housing while keeping the top pins and springs in place.
- Removes the old key pins.
- Puts in new key pins sized to match the cuts on a new key.
- Reassembles the cylinder, tests it with the new key, and reinstalls it.
The result: the new key works and every old key stops working. The lock body, the deadbolt, the handle and the finish all stay the same. Nothing about the lock’s strength changes. It is the same lock with a new combination.
When rekeying is enough
Rekeying is the right move when the hardware is in good shape and you simply need control over who can get in. Common cases:
- You just moved in. You don’t know how many copies the previous owner, contractors, or neighbors still have.
- You lost a key or someone’s keys were stolen.
- A tenant moved out. Landlords rekey between tenants so the last renter’s keys don’t work. See our page on rekeying after a tenant vacates.
- A roommate, ex-partner, house sitter or cleaner had a key and no longer should.
- You want one key for every door. If your locks share the same keyway (often the same brand), they can usually be rekeyed to work with a single key.
Our rekey service covers homes, apartments and businesses, and we come to you.
When you should change the locks instead
Replacement makes sense when the lock is part of the problem. Choose new locks if:
- The lock is worn out. Keys stick, the bolt drags, or you have to jiggle the key. Rekeying a worn cylinder won’t fix a tired mechanism. Sometimes a lock repair solves it; sometimes replacement is smarter.
- The lock was damaged or forced. After a break-in or attempted break-in, check the cylinder, bolt, strike plate and door frame. Damaged hardware should be replaced.
- The locks are cheap or very old. Builder-grade locks are often easy to defeat. Rekeying keeps that weakness.
- You want better security. Locks with pick-resistant and bump-resistant features, restricted key duplication, or a stronger bolt are an upgrade rekeying can’t provide. Learn more about high-security locks.
- Your locks are mixed brands with different keyways and you want one key. Replacing some of them with matching hardware may be the only way.
- You want keypad or keyless entry. Codes are easy to change any time, and there’s no key to lose.
- You’re remodeling and want new hardware that matches.
If you’ve already bought your own locks, we can install customer-supplied hardware too. Our lock installation page explains how that works.
Rekey vs. replace at a glance
| Rekeying | Changing locks | |
|---|---|---|
| What changes | Internal pins and keys | Entire lock |
| Old keys stop working | Yes | Yes |
| Improves lock strength | No | Yes, if you choose better hardware |
| Fixes worn or broken parts | No | Yes |
| Hardware cost | Pins only | Full new lock |
| Best for | Good locks, unknown key holders | Worn, weak, damaged or outdated locks |
Cost trade-offs
Rekeying is usually less expensive than replacing because you’re paying mainly for labor and a few small pins, not new hardware. Replacement adds the cost of the lock itself, and that varies a lot between a basic deadbolt and a high-security or keypad model.
Things that affect the final price either way:
- Number of locks and whether they should all work on one key
- Type of lock (standard deadbolt, handle set, mortise lock, commercial cylinder, high-security)
- Condition of the lock and door, since sticking bolts or misaligned strikes take extra time
- Time of day, since after-hours work costs more than scheduled daytime work
- Number of new keys you need
One practical tip: if you’re doing several doors at once, have everything done in one visit. It’s usually more efficient than separate calls. For more on what drives price, see our locksmith cost guide, or call 704-905-6600 for a quote on your specific locks.
Security trade-offs to think about
Rekeying solves a key control problem. It resets who can open your door. It does nothing for physical security: how well the lock resists picking, bumping, drilling or a kick to the door.
A few points worth knowing:
- Most forced entries attack the door, not the lock’s pins. A strong deadbolt with a reinforced strike plate and long screws that reach the wall framing matters more than which key you carry. Whether you rekey or replace, ask about the strike plate.
- Standard keys can be copied almost anywhere. If you’re worried about people making copies, consider restricted keyway locks, where duplicates are controlled.
- Keypad locks shift the risk. No key to lose, but you need to change codes when people move on and keep batteries fresh.
- Businesses have extra needs. When an employee leaves or keys go missing, a master key system or access control can limit what each key or credential opens. Rekeying alone may not be enough for a building with many doors and users.
A quick way to decide
Ask yourself three questions:
- Do the locks work smoothly? If no, lean toward repair or replacement.
- Am I happy with how strong and how good-looking they are? If no, replace.
- Is my only concern old keys? If yes, rekey.
Many people end up doing both: rekeying the locks that are in good shape and replacing the one or two that are worn or weak, all keyed to one new key. That often gives the best balance of cost and security.
If you’re in the Charlotte area and want a second opinion, our technicians can look at your locks on site and tell you which ones are fine to rekey and which ones are worth replacing.