Rekeying vs. Replacing Locks: How to Decide What You Need

If you've lost a key, moved into a new place, or aren't sure who still has a copy, you'll usually hear about two options: rekey the locks you have, or replace them. Both end with the old keys no longer working. The difference is what gets changed, and that affects which one fits your situation.

What rekeying actually changes

Many common residential door locks use a pin tumbler cylinder. Inside the cylinder is a row of small pins of different lengths. When the correct key is inserted, its cuts line those pins up so the cylinder can turn. A different key lines them up differently, and the cylinder stays put.

Rekeying means changing those internal pins so they match a new key. The lock body, the handle, the deadbolt, and the finish all stay on the door. Only the combination inside the cylinder changes. Once it's done, the old keys stop working and the new keys work.

Because the hardware stays in place, rekeying tends to make sense when:

• The locks work smoothly and you're happy with how they look and feel
• You want old keys to stop working, for example after a move, a lost key ring, or a change in who lives in the home
• You'd like several doors to open with one key, and the locks are compatible with each other

What replacing a lock changes

Replacement removes the existing lock hardware and installs new hardware. That can mean a new deadbolt, a new knob or lever set, a new handleset, or a different kind of lock altogether, such as a keypad or smart lock.

Replacement tends to make more sense when:

• The lock is worn, sticky, loose, or damaged, and a repair isn't practical
• You want a different style, finish, or function, like a lever instead of a knob
• You want a lock built to a different performance level
• The existing locks come from different makers and don't share a key design, so they can't be set to one key
• A door was forced or damaged and the hardware may no longer be reliable

New locks come with new keys, so replacement also takes care of the old-key problem.

Grades and ratings: what the labels mean

Door hardware packaging sometimes lists a performance grade. The Builders Hardware Manufacturers Association (BHMA) publishes ANSI/BHMA standards that sort many hardware products into grades 1, 2, and 3, with grade 1 set at the highest tested level. BHMA also runs a residential certification program that rates locks separately for security, durability, and finish.

These labels describe how a product performed in standardized testing. They don't describe how well it will be installed, and a sturdy lock on a weak or misaligned door frame won't perform the way the label suggests. If you're comparing options, it helps to look at the whole door: the frame, the strike plate, and how cleanly the door closes.

Questions that help you decide

Walk through these before you ask for a quote.

1. Do the locks turn smoothly with the key and latch without pushing or lifting the door? If so, rekeying is often a reasonable place to start.
2. Are you happy with the look and function of the hardware? If you'd like a change anyway, replacement may be the better fit.
3. How many doors are involved? Count every exterior door, including a side door, the door from the garage into the house, and any door to a basement or back porch.
4. Do you want one key for everything? Check the brand name on each lock. Locks from different makers often use different key shapes, which can limit keying them alike.
5. Is anything damaged? Cracked frames, bent bolts, or loose hardware point toward repair or replacement rather than rekeying alone.

Things that affect the quote

Whichever route you take, the price depends on the details of the job rather than a single flat number. Common factors include:

• How many locks and cylinders are involved
• The type and brand of each lock
• Whether you want locks keyed alike
• Whether new hardware is needed, and what kind
• How many new keys you want
• The condition of the door, including any adjustments needed for the lock to work properly

Asking what's included and what could change the total is a good habit with any locksmith. Our guide to understanding a locksmith estimate walks through those questions in more detail.

What to have ready

• A list or photos of each lock, including the brand name if it's visible
• A note about any lock that sticks, spins, or doesn't latch
• Your working keys for each lock, if you have them
• Photo ID and a document that shows you live at or own the property, such as a lease, closing paperwork, or a utility bill in your name

That last point matters. A responsible locksmith confirms that the person asking is authorized to have the locks changed. Expect that check as part of the service process, and know that it protects you as well.

Limitations to keep in mind

• Rekeying only affects the cylinder. It won't fix a worn latch, a misaligned door, or a damaged frame.
• Some locks, including certain older, low-cost, or proprietary designs, aren't practical to rekey.
• Many smart locks have both a physical key cylinder and a digital side. Changing the key doesn't remove old user codes or app access, and those need to be reset separately.
• If you rent, check your lease and talk with your landlord before changing or rekeying any lock.

Next step

If you'd like help deciding, you can describe your doors and what you're hoping to change through our contact page. Photos and brand names help the conversation start in the right place. Moving soon? Our new home lock checklist covers the other keys, codes, and openers worth tracking down.