How to Rekey a Lock, and When to Call a Locksmith
- Rekeying keeps the lock and changes the key. Replacing swaps the whole lock.
- Kwikset SmartKey locks rekey with a learn tool and the current key, no disassembly.
- Standard pin tumbler locks need the cylinder removed and a kit matched to the brand.
- No working key, high security cylinders and whole house jobs are where a locksmith earns the fee.
What Rekeying Changes Inside the Lock
Most house locks are pin tumbler locks. Inside the cylinder sit small stacks of pins pushed down by springs. Each stack has a key pin at the bottom and a driver pin on top. The right key lifts every stack so the gap between the two pins lines up with the edge of the plug. That line is called the shear line. When every gap sits on it, the plug turns.
Rekeying means swapping the key pins for new lengths that match a new key. The lock body, the bolt and the finish all stay. Only the code changes. Our guide on whether to rekey or replace covers when that is enough and when it is not.
Method One. Kwikset SmartKey Locks
Kwikset SmartKey locks were built to be rekeyed by the owner. You need the key that works now, the new key and the SmartKey learn tool. The new key must be the same Kwikset key type.
- Put the working key all the way in and turn it a quarter turn clockwise.
- Push the learn tool firmly into the small hole next to the keyway until it clicks.
- Pull the old key out. Leave the learn tool where it is.
- Put the new key all the way in and turn it back a quarter turn to the start.
- Take the learn tool out and test the new key several times with the door open.
If it does not take, start again from step one with the original key. Do not force the tool. The exact steps for your model are in the instructions that came with the lock or on the maker site.
Method Two. Rekey Kits for Standard Locks
Most other locks need the cylinder taken out. Hardware stores sell rekey kits for common brands like Kwikset and Schlage. A kit usually holds pins in several sizes, a plug follower, a pinning tool and a chart. The rough order is the same for most brands.
- Take the knob, lever or deadbolt off the door and remove the cylinder. On knobs this often means a small clip or retainer.
- Put the working key in, turn it slightly and push the plug out with the follower. The follower holds the driver pins and springs in place. If it slips, they can shoot out.
- Tip out the old key pins.
- Put the new key in the plug and drop in key pins until each one sits flush with the top of the plug. The chart helps you pick sizes.
- Slide the plug back in while pushing the follower out, so nothing falls loose.
- Put the lock back together and test it many times with the door open.
It is a careful job, not a hard one. The usual mistakes are losing springs, mixing up pin sizes and testing with the door shut. Work on a towel on a table, not on the floor by the door.
Can You Rekey a Lock Without the Key?
A homeowner usually cannot. Both methods above need the working key to turn the plug. Without it the cylinder has to be picked or decoded first, which is locksmith work. This is the most common reason a DIY rekey turns into a service call. If you just moved in and nobody handed you keys, read our guide to the locks to change when you move in first.
When a Locksmith Is the Better Call
- You have no working key for one or more locks.
- You want every door on one key. Matching several brands to one key is easier with a locksmith who carries blanks and pins.
- The lock is high security. Brands with patented keys or extra sidebars are built not to be rekeyed with a store kit.
- You are a landlord or a business. Many doors and a master key system call for planning and records. See our lesson on master key theory.
- The lock is worn. If the key sticks or the bolt drags, rekeying will not fix that. Replacing might.
Our locksmith cost guide gives the usual price ranges for rekeying so you can compare the call with a kit and an afternoon.
Before You Start
Check the brand stamped on the lock face or the key. Buy the kit for that brand. Take a photo of each step as you take the lock apart. Keep a spare working key on hand until you have tested the new one. If anything feels stuck or broken, stop and put it back together with the old pins. A locksmith can finish the job, and a partly rekeyed cylinder is easy for them to sort out.
When you want help, you can find a locksmith by city on our directory.
Common Questions
Is rekeying cheaper than replacing a lock?
Usually yes. You keep the hardware and only change the pins. Replacing makes more sense when the lock is worn, damaged or too weak for the door.
Can I rekey a Schlage lock myself?
Many standard Schlage locks can be rekeyed with a Schlage rekey kit if you have the working key. Without the key, a locksmith is the practical choice.
How long does it take to rekey a lock?
A SmartKey lock takes a minute or two. A standard cylinder with a kit takes longer, especially the first time, because you have to remove and rebuild it.
Does rekeying make a lock more secure?
It makes old keys useless, which is the point. It does not make a weak lock stronger. For that, look at the lock grade and the strike plate.