The day you close on a new home — or sign the lease on a rental — you should already know how many people have working keys to your new front door. The honest answer is almost always “I have no idea.” Builders, contractors, previous tenants, real estate agents, cleaners, the seller’s in-laws — any of them could still have a key that unlocks the door you’re going to be sleeping behind tonight.

The fix is one of the cheapest security upgrades in homeownership: a rekey, or occasionally a full lock replacement. This post walks through which one you need, what it costs, and why this job should happen before you unpack the moving truck.

First, the vocabulary

Rekeying changes the internal pin configuration of a lock so old keys stop working. The hardware itself — the deadbolt, the knob, the finish, the cylinder body — stays exactly the same. A locksmith pops the cylinder out, rearranges the pins, and cuts a new set of keys that match the new configuration. Total time: 10-15 minutes per lock.

Replacing a lock swaps the entire hardware for something new. This is what you do when the existing lock is worn out, damaged, below current security grade, or you want to switch to a smart lock. Total time: 20-30 minutes per lock.

Keyed alike means multiple locks share the same key. If you rekey your front deadbolt, back deadbolt, side gate, and garage-to-house door all to the same new pin configuration, you carry one key instead of four.

When you should rekey

Rekey when the existing hardware is in good working order and you just need to change who has a working key. That covers these common move-in scenarios:

  • Just bought a home. You don’t know how many keys were floating around — real estate agents, contractors who worked on the property pre-sale, the seller’s family, the cleaning service. Rekey on day one.
  • Just signed a lease on a rental. In California, landlords are generally required to rekey between tenants, but it doesn’t always happen. If your new landlord can’t confirm the rekey, ask for it in writing or pay for it yourself.
  • Ended a roommate or co-tenant arrangement. When someone with a working key moves out on bad terms, rekey before they decide they forgot a jacket.
  • Lost a key somewhere. If you can’t locate a key and it has nothing that identifies the address (no tag, no house-shaped keychain), the risk is usually low. But if there’s any chance it’s findable and traceable — keys in a lost wallet, keys dropped at work with a parking pass attached — rekey.
  • Fired a contractor or housekeeper who had a key. Happens regularly. Rekey, don’t trust the return.

When you should replace instead

Replacement is the right call when the existing hardware isn’t worth rekeying. Signs it’s time to upgrade:

  • The lock feels loose, sticky, or wobbly. Grade-3 builder-grade locks that have been abused for 10+ years often fail mechanically. A rekey fixes the key problem but not the mechanical problem.
  • The finish is pitted, corroded, or rusting. Particularly on coastal homes in Coronado, Del Mar, Imperial Beach, Solana Beach, and the North Coastal cities — salt air wears out low-quality finishes in 8-10 years.
  • The lock is ANSI Grade 3 on an exterior door. Grade 3 is builder-grade — fine for an interior closet, inadequate for a front door. If you’re rekeying anyway, spend the extra to upgrade to Grade 1 or Grade 2 at the same time.
  • You want a smart lock. You can’t retrofit a smart lock onto a mechanical deadbolt via rekey — you need new hardware.
  • Recent attempted break-in. Even if the lock wasn’t damaged, the attempt may have stressed the cylinder. Replace to be safe.

What it costs in San Diego

Rekey pricing in San Diego County (2026):

  • Per cylinder: $25 to $40
  • Service call fee: $29 (waived on jobs of 3+ locks)
  • Typical 2-exterior-door home, keyed alike: $80 to $110 all-in
  • Typical 4-door home (front + back + side + garage), keyed alike: $115 to $170

Replacement pricing:

  • Grade-2 deadbolt (Kwikset 980, Schlage B250): $120 to $180 installed
  • Grade-1 deadbolt (Schlage B60, Medeco Maxum): $180 to $280 installed
  • Smart deadbolt install (hardware + pairing + setup): $180 to $420 installed

A rekey is 70 to 80 percent cheaper than a full replacement and solves the same key-control problem. Most move-in situations only need rekeying.

The “keyed alike” advantage

If you have more than one exterior lock, ask for keyed-alike rekeying. It costs nothing extra beyond the per-cylinder rekey price, and it collapses your keychain from four keys to one. The locksmith pins every cylinder to the same configuration, and you get a single key that opens:

  • Front deadbolt
  • Back or patio deadbolt
  • Side gate
  • Garage-to-house door
  • Shed lock (if it’s a standard Kwikset or Schlage)

Keyed alike is the single most underrated benefit of a rekey — the practical convenience is massive, and you pay nothing extra for it.

Restricted keyways: a step beyond standard rekey

If you live in a higher-security neighborhood (Rancho Santa Fe, Fairbanks Ranch, parts of La Jolla, Poway, or any home with concerns about unauthorized key duplication), consider a restricted-keyway rekey using Medeco, Mul-T-Lock, or Abloy.

Restricted keyways use patented key shapes that hardware stores and kiosks can’t legally duplicate. To get a copy made, the authorized key holder has to return to the original locksmith (us, in this case) with ID. This is useful when:

  • You’re renting out a property and want to know exactly how many keys are in circulation
  • You have a housekeeper, contractor, or family member who might duplicate a regular Kwikset key without asking
  • You want audit-level key control — something standard residential keyways can’t provide

Restricted keyway systems cost more: typically $200-$400 for the first cylinder plus additional keys at $25-$75 each. For standard residential use, a regular rekey is fine.

What to do about the mail / mailbox key

Most San Diego homes use USPS cluster mailboxes with their own key system (Arrow 21680 or similar). These are not rekeyed — USPS controls the key configuration for cluster boxes. If you move into a home where the previous resident didn’t return the mailbox key, contact your local USPS office to request a replacement. They’ll rekey the box for a small fee and provide new keys to the verified resident.

Private mailboxes (wall-mounted, not cluster) can be rekeyed by a locksmith if they use a standard keyway. Bring it to us during the rekey call.

A sample move-in day plan

For a typical San Diego home purchase or rental move-in:

  1. Day of close / move-in: call to schedule a rekey for the next business day
  2. Day 1 in the house: locksmith rekeys all exterior doors to one new key, confirms the strike plates aren’t worn or loose, upgrades any Grade-3 deadbolts to Grade 1 if you want
  3. Day 2: contact USPS to request a mailbox-key reissue if the previous resident didn’t hand theirs over
  4. Day 3-7: install a smart lock on the front door if that’s on your list — or keep it simple with the rekeyed traditional hardware

Total cost for this workflow on a 2-door home: around $100 for the rekey, plus $180-$420 if you add a smart lock. It’s the cheapest major security upgrade you’ll do as a homeowner, and it solves a real problem.

Just moved in and need a rekey? Swift Key San Diego does mobile rekey service across every city in San Diego County. Typical job takes 30-45 minutes for a standard 2-door home. Call (858) 808-6055 — same-day availability most weekdays.