How to rekey or replace every exterior lock
Rekey or replace locks on every exterior door as soon as you get the keys. Rekeying swaps the pins so old keys stop working, and it costs less than new hardware. A single-lock kit runs about $12 to $25. Replace a lock instead if it's worn or damaged, or you have mixed brands.
Rekey or replace locks: how to choose and what to get
Start by deciding between two jobs. Rekeying changes the pins inside the lock so it takes a new key. Replacing swaps the hardware. Independence, Missouri, police tell people to re-key all locks on moving into a new house, since many burglaries happen with no forced entry, often because the burglar has a key.
| Your situation | Do this |
|---|---|
| Locks work well and are the same brand | Rekey |
| You want one key for every door | Rekey to match, if all locks are one brand |
| Mixed brands | Replace the odd ones so everything matches, then rekey |
| Lock is cracked, warped or worn | Replace |
| No working key for that lock | Replace, or call a locksmith |
Brand matters because keyways differ. Bob Vila's guide gives the example that you can't rekey a Kwikset lock to take the same key as a Schlage. A DIY kit is brand-specific, so check the name on the lock face before you buy. Each kit includes picks, tweezers, a key gauge, and new pins and springs, and some cover up to five locks.
If you're replacing a deadbolt, also look at the door. Irvine police want a deadbolt with at least a 1-inch throw, and you can match it with a stronger strike plate at the same time.
Which doors to cover when you rekey locks in a new house
Count every lock that opens to the outside or to something you'd miss. People tend to remember the front door and forget these:
- The door from the garage into the house
- Basement and side doors
- Sliding door locks, if they take a key
- Gates, sheds and padlocks
- Keypads and smart locks, which need new codes and removed app users rather than new pins
- Any lockbox an agent or contractor used
Once the locks are done, take control of the keys. Police advice is consistent: don't hide a key outside, because burglars know the hiding places, and that includes under a doormat. Leave a spare with a trusted neighbor. Know who holds each key, don't put identifying tags on your key ring, and don't hang keys in plain view inside the home.
How to rekey a lock, from counting to testing
- Count your locks
Walk the outside of the house and list each door, gate and padlock, with the brand on each lock.
- Decide rekey or replace
Check each lock turns smoothly and isn't cracked or worn. Replace any that fail, and any odd brands.
- Choose who does it
Compare a kit, a store counter and a locksmith visit for your number of locks.
- Rekey the cylinders
Follow the kit's instructions, or take the locks to the counter with the current key. Work on a tray, because the pins and springs are tiny.
- Test every key in every lock
Do this with the door open, so you can't lock yourself out.
- Reset digital access
Change keypad and smart lock codes, and remove old users from any app.
- Clear out hidden keys
Check under mats, in fake rocks and above door frames, then give one spare to someone you trust.
Lock rekeying cost for kits, stores and locksmiths
| Option | About what it costs | What it covers |
|---|---|---|
| DIY rekey kit | $12 to $25 for a single-lock kit | Tools and pins for one brand; larger kits cover up to five locks |
| Hardware store, lumberyard or locksmith counter | About $5 per lock | You remove the lock and bring the current key |
| Locksmith at your house | $40 to $100 service call, plus $10 to $30 per lock | They do the work on site |
| New deadbolts or locksets | Varies by grade and finish | Needed for worn locks or mixed brands |
As a worked example using those figures, a locksmith rekeying four locks would come to about $80 to $220. Prices vary by area, and after-hours calls can cost more.
Mistakes to avoid when you rekey or replace locks
- Waiting until the boxes are unpacked. Do this before your first night if you can.
- Buying a kit before checking the lock brand.
- Rekeying without the current key. You need it to take the lock apart.
- Skipping a lock because it's rarely used. A forgotten door is still a door.
- Leaving the seller's smart lock users in place. Rekeying won't remove a code.
What homeowners say about how to rekey a lock
Owners say to book the locksmith for closing day or show up with new locks and a drill. One had a locksmith there an hour after closing. A seller in one thread admitted their son had lost his key five times and they had given copies to about six pet sitters, so assume keys are scattered around the neighborhood. (Reddit)
Price it before you call a locksmith. One owner paid over $150 for a house call. Others rekeyed four locks in about an hour with a roughly $15 pin kit, or took the cylinders to a hardware store counter that rekeys them. Some say new $30 locksets cost about the same as a locksmith visit. (Reddit)
If you switch to a keypad lock, owners say to pick one that still takes a physical key, so a dead battery can't lock you out. Replace the battery the first time the bolt struggles to throw. One owner waited too long and got locked out. Codes usually survive a battery swap. (Reddit)
In new subdivisions, builder locks often carry construction or master-key pins, so neighbors' keys may be closer to yours than you'd like. Rekeying fixes this. Kwikset-compatible pin kits are cheap, and a locksmith can rekey everything to one key if you bring the cylinders in. (Hacker News)
If you rely on Kwikset SmartKey self-rekeying, use a factory-cut key, not a copy. Owners report jammed cylinders after rekeying with a key that didn't fully seat, and one locksmith steered people away from these locks. (DIY Stack Exchange, Hacker News)
Where owners disagree: Most owners say anyone can rekey or swap locks and you don't need a pro. One owner disagrees from experience: their first try left a door that wouldn't lock, the second left one that wouldn't close, and they had no signal to pull up a video. A locksmith fixed it and can install a reinforced strike plate in the same visit. If you're not handy, budget for the locksmith. (Reddit)
Where owners disagree: Keypad deadbolts get a lot of love; several owners say they'd never go back to keys and like giving guests codes. A security-minded minority says most electronic locks are easier to defeat than a good grade 1 mechanical deadbolt installed with long screws. One keypad owner answers that a burglar can break a window anyway, so the lock isn't the weak point. (Reddit)
Where owners disagree: Handy and cheap, but owners report jammed cylinders after rekeying with a copied key, and a locksmith advised against them. Security researchers have also shown weaknesses in some generations. (DIY Stack Exchange, Hacker News)
Questions on when to rekey or replace locks
Is it cheaper to rekey or replace locks?
Rekeying usually costs less when the hardware is sound. Replacing makes sense when a lock is worn or damaged, or you need to match brands.
Can all my locks use the same key?
Yes, if they're the same brand. Different brands have different keyways, so replace the odd ones first and then rekey them to match.
Can I rekey a lock without the key?
Generally not with a DIY kit, because you need the working key to take the lock apart. Replace the lock or call a locksmith.
What you’ll need
Sources: Bob Vila, independencemo.gov, irvinepd.gov
General guidance for U.S. homes, not professional advice. For gas, electrical and structural work, call a licensed pro.