Maybe you just got the keys to a place in Ballard, a roommate moved out of your Capitol Hill apartment, or a key went missing between the car and the front door. The fix is the same: rekey the lock so the old keys stop working. It sounds technical, but the core idea is simple, and on a lot of common locks it is something a careful homeowner can do at the kitchen table. Below is what rekeying actually does, the pin-and-tumbler basics behind it, how DIY kits and Kwikset SmartKey compare to hiring a locksmith, a plain step overview, and where the do-it-yourself route runs out of road. Prices here are typical Seattle market ranges, not fixed quotes, so use them as a guide and get a firm itemized price before any paid work starts.
What rekeying a lock actually means
Rekeying changes the inside of a lock so it opens with a new key and refuses the old one. Nothing leaves the door. The deadbolt, the knob, the strike plate, the screws, all of it stays put. What changes is a set of tiny pins inside the cylinder, the part the key slides into. Swap those pins to match a different key and the lock now belongs to that key alone.
That is why rekeying exists as a separate job from replacing a lock. After a home sale or a tenant turnover, the hardware is usually fine. The problem is that you have no idea how many working copies of the old key are floating around with agents, stagers, cleaners, or a former tenant. Rekeying resets that count to zero without spending a dime on new hardware. For where this sits against every other locksmith task, our guide to what a locksmith costs in Seattle lays out the full menu.
The pin-and-tumbler basics (why a key turns at all)
You only need a one-paragraph picture of how a standard lock works. Inside the cylinder are several small chambers, usually five or six. Each holds a spring, an upper driver pin, and a lower key pin. With no key in the lock, the springs push the pins down so they straddle the gap between the rotating plug and the fixed housing, and that straddle jams the plug in place.
The right key has a series of cuts at different depths. Each cut lifts its key pin to exactly the height where the split between the key pin and the driver pin lines up with that gap, called the shear line. When every pin reaches the shear line at once, the plug is free to rotate and the bolt moves. A wrong key lifts the pins to the wrong heights, at least one split misses the shear line, and the plug stays locked.
Rekeying is just changing which key heights work. A locksmith or a rekey kit swaps the key pins for a different set of depths so the cuts on a new key line up at the shear line, and the old key no longer does. The springs and driver pins usually stay. That is the entire trick, and it is why rekeying is mechanical work, not magic.
Your three options for rekeying
There are three ways to get a lock rekeyed, and they fit different situations. The cheapest one on paper is not always the cheapest once you count your time and the number of doors.
Option 1: A standard rekey kit
Brands like Kwikset and Schlage sell rekey kits for around $10 to $25. A kit is a small tray of replacement pins in graded depths, a plug follower, a cylinder removal tool, and one or two new keys cut to a fresh combination. You take the lock apart, pull the old key pins, drop in the pins that match the kit’s new key, and reassemble. Reuse the same kit on other locks of the same brand and keyway and they all end up working on that one key.
Option 2: Kwikset SmartKey (no tools, no pins)
Kwikset SmartKey is a different mechanism built specifically so anyone can rekey it in under a minute. There is no need to open the cylinder or handle loose pins. You insert the current working key, push a small SmartKey reset tool into a side port, turn the key a quarter turn, pull it out, insert the new key, and turn it back. The lock now answers to the new key. SmartKey hardware runs about $25 to $60 for a re-keyable deadbolt. It is genuinely the easiest option, with one honest trade noted below.
Option 3: Hire a locksmith
A locksmith brings the pins and tools to your door and rekeys whatever you have, including mismatched brands, to a single key. In the Seattle area this typically runs about $25 to $75 per lock plus a $50 to $100 service call, so a full house of three to five doors lands around $150 to $300 all in. You pay more than a kit, but you get keyed-alike doors, no dropped springs, and the whole job done in one visit. Our guide to choosing the right locks for your Seattle home pairs naturally with rekeying after a move.
How to rekey a lock yourself: the step overview
This is the general flow for a standard pin-tumbler deadbolt using a rekey kit. It is an overview, not a substitute for the instructions in your specific kit, and it assumes you have the current working key in hand. Work over a tray or a towel, because the springs and pins are small and they like to roll away.
- Remove the lock from the door. Take out the two screws on the interior side and lift the deadbolt halves off. You usually only need the exterior cylinder.
- Free the cylinder. Following the kit, remove the retaining clip or ring that holds the plug in the housing. Keep that clip somewhere safe.
- Insert the current key and rotate the plug. With the working key in, turn the plug slightly so it clears the housing.
- Push the plug out with the follower. Slide the plug follower in behind the plug so it holds the driver pins and springs in place while the plug comes out the front. This is the step people rush and regret, because if the follower slips, the springs launch.
- Swap the key pins. Remove the old key pin from each chamber and drop in the pin depth the kit specifies for its new key.
- Slide the plug back in. Push the plug back through, driving the follower out the back so the driver pins and springs settle onto the new key pins.
- Reassemble and test. Replace the retaining clip, reinstall the lock on the door, and test the new key several times locked and unlocked before you trust it. Confirm the old key no longer turns it.
SmartKey skips almost all of this. With a SmartKey lock you only do the insert, reset tool, quarter turn, swap keys, turn back sequence, with the lock still on the door. That is the real appeal of the SmartKey design for a homeowner who just wants one door changed fast.
The catch with DIY: kits are brand and keyway specific
Here is the limitation nobody mentions on the box. A rekey kit only works on locks that share its brand and keyway. A Kwikset kit rekeys Kwikset KW1 cylinders. A Schlage kit rekeys Schlage SC1 cylinders. They are not interchangeable, and the pin sizes are different. If your front door is a Schlage and your back door is a Kwikset, one kit cannot do both, so you are buying two kits and learning two slightly different procedures.
The second limit is the key itself. A kit rekeys your lock to the new key the kit supplies, not to any key you choose. If you want three doors to open with one key, every one has to be the same brand and keyway and rekeyed to that same kit’s key. The moment your doors are a mix of brands, getting them all onto a single key yourself stops being practical. That is where a locksmith earns the fee, because pinning mismatched cylinders to one customer key is routine for them and a headache for you.
SmartKey has its own honest trade. The mechanism that makes it tool-free to rekey also makes it somewhat easier to pick or bump than a traditional high-grade pin cylinder. For an interior door or a low-risk entry it is fine and convenient. For a primary exterior door, weigh that against a solid Grade 1 traditional deadbolt. Our roundup of the best front door locks for a Seattle home covers grades and real options worth considering.
Cost comparison: DIY vs hiring a pro in Seattle
The price gap looks large until you count doors, brands, and your own time. A kit is cheapest for a single door of a single brand. A locksmith wins as soon as you have several doors, mixed brands, or you want everything keyed alike.
| Approach | Typical Seattle cost | Best for |
|---|---|---|
| Standard rekey kit (Kwikset/Schlage) | $10 – $25 per keyway | One brand, one or two matching doors |
| Kwikset SmartKey re-keyable deadbolt | $25 – $60 hardware | Easiest DIY, tool-free reset, single door |
| Locksmith, per lock | $25 – $75 | Labor and pins, same hardware, old keys dead |
| Locksmith service call / trip fee | $50 – $100 | One-time per visit, covers travel and setup |
| Locksmith full house rekey (3 – 5 locks) | $150 – $300 all in | Mixed brands, keyed alike, one visit |
Read the table this way. One Kwikset deadbolt and a free afternoon means a kit or a SmartKey swap is the sensible call. A home with five doors from three different makers that you want on one key means paying $150 to $300 to a locksmith is less total money than several kits plus the time, and you skip the risk of a sprung pin leaving a door unsecured overnight. The honest middle ground is common too: rekey the easy matching doors yourself and have a pro handle the oddballs.
When DIY is fine and when to call a pro
You do not need to guess which lane you are in. Run your situation down this list.
| Your situation | DIY or pro | Why |
|---|---|---|
| One or two doors, same brand, you have the working key | DIY kit | Cheap, well within a careful homeowner’s skill |
| Single door, want the easiest possible reset | DIY SmartKey | Tool-free, under a minute, no loose pins |
| Several doors of mixed brands, want one key | Pro | One key across mismatched cylinders is routine for a locksmith |
| No working key (lost or stolen, none left) | Pro | Most kits and SmartKey need the current key to start |
| Lock sticks, drags, or feels worn | Pro (and consider replacing) | Rekeying a failing cylinder just delays the problem |
| High-security or restricted-key cylinder (Medeco, Mul-T-Lock, Abloy) | Pro | Proprietary parts and pinning, not a retail kit |
| You are a renter | Pro or DIY, with permission | Confirm with your landlord or property manager first |
The pattern is consistent. DIY is genuinely fine for simple, single-brand, working-key situations, and there is no reason to pay a service call for one matching pair of Kwikset deadbolts. The moment the job involves no working key, mixed brands keyed to one key, worn hardware, or a high-security cylinder, a pro is faster, cleaner, and often cheaper once you total everything. If you have no key at all, that is a different job, closer to our guide on being locked out of the house in Seattle.
One thing rekeying does not fix
Rekeying changes who has a key. It does not upgrade a weak door. If a previous owner installed a builder-grade Grade 3 lock on an exterior door, rekeying it leaves you with a Grade 3 lock that simply takes a new key. For exterior doors, ANSI/BHMA Grade 1 is the highest residential grade and the right target, with Grade 2 a solid mid-tier and Grade 3 belonging on interior doors. A full 1-inch deadbolt throw seats deep and resists prying, and one of the cheapest real security gains is swapping the short factory strike-plate screws for 3-inch screws that bite into the wall framing, ideally with a reinforced strike box. So when you change your keys after a move, look at the grade and the strike too, and replace rather than rekey any door where the hardware itself is the weak link.
Frequently asked questions
Can I rekey a lock myself?
Yes, for many common locks. If your deadbolt takes a rekey kit that matches its brand and keyway, or if it is a Kwikset SmartKey lock, a careful homeowner can rekey it in about 10 to 20 minutes with basic tools. The catch is that kits are brand and keyway specific, you can only rekey to the keys the kit supplies, and matching several doors to one key gets fiddly. If you have many doors, mismatched brands, or a worn or high-security cylinder, hiring a locksmith is usually faster and cheaper than buying multiple kits.
What does it actually mean to rekey a lock?
Rekeying changes the small spring-loaded pins inside the lock cylinder so it works with a new key and the old key no longer turns it. The lock itself, the deadbolt, the knob, and the strike all stay on the door. You are not buying new hardware, you are resetting which key opens the lock you already have. That is why it is the standard step after a home sale, a roommate move-out, or a lost key.
How much does it cost to rekey a lock in Seattle?
A DIY rekey kit runs roughly $10 to $25 and covers one keyway, plus you reuse it on matching locks. Hiring a locksmith in the Seattle area typically costs about $25 to $75 per lock plus a $50 to $100 service call, so a full house of three to five doors lands around $150 to $300 all in. The pro price buys keyed-alike doors, mixed brands handled in one visit, and no risk of dropping tiny springs. Always get a firm itemized quote before work begins.
Is a rekeyed lock as secure as a new one?
Yes. Rekeying does not lower the grade or strength of the lock. A rekeyed Grade 1 deadbolt is exactly as secure as it was the day it was installed, because security comes from the quality of the hardware, not from whether the key is new. The one caveat is Kwikset SmartKey and similar DIY-friendly mechanisms, which trade some pick and bump resistance for easy rekeying. If a door is low grade or worn, the answer is to replace it, not to skip rekeying.
Need it rekeyed right, the first time? Call WA Lock & Key
WA Lock & Key is a Seattle-based 24/7 mobile locksmith, so we come to you anywhere across the metro and rekey your doors on site, mixed brands and all, to a single key if you want one. If you have already tried a kit and a spring got away from you, or you bought a home in Queen Anne and want every exterior door changed on day one, we will walk your doors with you, tell you honestly which ones are worth rekeying and which should be replaced, and give you a firm itemized quote before we touch anything. Call us and we will tell you exactly what your doors will cost before we start.
