Yes, rekey the locks. Not replace them. Rekeying runs $25 to $40 per cylinder, takes 10 minutes per lock, and leaves you as the only person with a working key. Whether the situation ended well or badly, the moment your roommate walked out with a copy of your key, your security situation changed. Here’s how to handle it correctly.
When rekeying after a roommate leaves actually makes sense
Not every roommate departure calls for a rekey. Here’s a straightforward way to think about it.
Rekey when:
The roommate kept a copy of the key and you can’t confirm it was returned. This is the most common scenario. Most people never track how many copies of a key exist. A spare in their desk, one at a parent’s house, the copy they made “just in case” three years ago. If you don’t have every key physically in hand, assume there’s one out there.
The split ended badly. Argument over the deposit, a relationship that went sideways, a subletter you never formally vetted because you were just trying to cover rent. Uncomfortable situations don’t have to turn into dangerous ones. A rekey is $25 to $40 per cylinder and it closes that chapter.
You never met the person who had a key. Subtenants, housemates arranged through a landlord, someone added to the lease by a former roommate. If you don’t know the person well enough to be confident they won’t test their old key, rekey.
Someone else had a key through your roommate. A partner who stayed over constantly, a family member with a spare. When your roommate moves out, those secondary key holders are still out there.
When it’s probably overkill:
The roommate moved out on good terms, you have every key back physically, and the relationship is genuinely solid. Grown adults you trust. If that’s actually your situation, you probably don’t need to rekey. Most people reading this aren’t in that situation, which is why you’re searching.
What rekeying actually involves (and the keyed-alike upsell, honestly explained)
A locksmith pops the cylinder out of your deadbolt, rearranges the internal pins, and cuts new keys to match. The hardware stays. The finish stays. Everything looks exactly the same. Your old key stops working, a new key works in its place.
Per cylinder: $25 to $40. Service call: $29 (waived when you’re doing three or more locks). Typical two-door San Diego apartment or condo all-in: $80 to $110. Takes 30 minutes start to finish.
The keyed-alike option is worth mentioning honestly here. If you have more than one exterior lock, a locksmith can pin all of them to the same configuration for no extra cost per cylinder. One key opens the front deadbolt, back door, side gate, and garage-to-house entry. This isn’t an upsell. It’s just logical if you have multiple locks and you’re paying for the service call anyway. Most people don’t know to ask for it.
If you only have one deadbolt and one door, keyed alike doesn’t apply. But if you’re in a house with two or three entry points, ask.
For a deeper look at the cost comparison between rekeying and full lock replacement, see Rekey vs. new locks: what’s the actual cost difference.
The rental permission question
If you’re a renter in San Diego, the short answer is: you generally need landlord permission before rekeying, and most leases require it. That said, most landlords will say yes immediately when you explain a roommate just moved out. Send a quick text or email. It’s a reasonable request and most property managers have dealt with this exact situation before.
If you own your unit or it’s your name on the deed, rekey freely.
The legal side of tenant rekeying rights in California goes deeper than one paragraph can cover well. Our full guide on tenant rekey rights in California walks through the details. The practical rule: ask your landlord, put it in writing, and most landlords will approve same-day.
The access points most people forget
A rekey covers your front door. That’s it. Most post-roommate security gaps aren’t the front door deadbolt. They’re everything else.
Garage codes. If your building or home has a keypad-entry garage, your former roommate almost certainly knows the code. Change it before anything else. Takes 30 seconds. This is the most commonly forgotten access point.
Gate fobs and building access cards. If your former roommate still has an HOA fob, building key card, or complex entry card, those work independently of your front door lock. Contact your HOA or property management to deactivate it. In most San Diego buildings, this requires a written request and takes a day or two.
Mailbox key. If you share a unit and your roommate had a mailbox key, they can still access your mail after they move out. For USPS cluster boxes (the standard for most San Diego apartment complexes), contact your local post office to request a rekey. They handle it for a small fee and provide new keys to the verified resident.
Spare keys hidden outside. Under a rock, in a fake rock, above the door frame. If your roommate knew where these were, move them or remove them entirely. Hidden spare keys are the most defeated security measure that people still use.
Alarm codes. If you have a home alarm system and your roommate knew the code, change it immediately. Every system is different but this is a three-minute task in the app or on the panel.
Wi-Fi password. Not a physical security item, but worth mentioning. A former roommate on your network is a lower-tier concern than the ones above, but it’s easy to change and worth doing if the situation ended badly.
The smart lock alternative (when it applies)
If you already have a smart lock installed, you don’t need a locksmith for the key problem specifically. Smart locks use numeric codes instead of physical keys. Deleting your former roommate’s code takes about 30 seconds in the app.
This is the fastest resolution when it applies. No scheduling, no service call, no cost. Just open the app, find their code entry, delete it.
The limitation: most San Diego apartments and older homes don’t have smart locks. If yours doesn’t, a smart lock installation during the same visit as a rekey is worth considering, especially if you anticipate future turnover in your living situation. A smart lock eliminates the rekey cost on every future roommate departure.
If you’re weighing the options, smart lock vs. deadbolt: which is actually safer walks through the tradeoffs without a sales pitch.
Cost and timing summary
| Item | Cost | Time |
|---|---|---|
| Rekey one cylinder | $25-$40 | 10 min |
| Service call fee | $29 (waived at 3+ locks) | |
| 2-door apartment, all-in | $80-$110 | 30 min |
| 3-door house, all-in | $105-$149 | 45 min |
| Smart lock install (hardware + setup) | $180-$420 | 45-60 min |
| Garage code change | Free | 2 min |
| Alarm code change | Free | 3 min |
| HOA fob deactivation | Varies by building | 1-2 days |
Same-day service is available across San Diego County most weekdays. If you call before noon, the job is usually done the same afternoon.
Frequently asked questions
Should I change the locks when a roommate moves out?
You should rekey, not replace. Rekeying is $25 to $40 per cylinder and changes the internal pin configuration so old keys stop working. The hardware stays the same. If the roommate left on good terms and you have every key physically back in hand, a rekey is optional. If there’s any doubt about outstanding copies, rekey before the first night sleeping there alone.
How much does it cost to rekey after a roommate leaves?
A standard San Diego apartment with two exterior doors runs $80 to $110 all-in for a rekey, including the service call. The service call fee ($29) is waived when you’re doing three or more locks. Each additional cylinder is $25 to $40, and asking for keyed-alike service adds nothing to the price. See lock rekey service for current pricing.
Can I rekey a rental myself?
Rekeying requires a pinning kit, the specific cylinder type, and some practice. It’s a learnable skill but not a beginner DIY task. More practically, most California leases require landlord permission for any lock modification. Get written approval from your landlord first, then decide whether to hire a locksmith or attempt it yourself. Most tenants hire a locksmith because the cost ($80-$110) is low relative to the risk of damaging the cylinder.
What if my roommate still has a fob or building access card?
Contact your HOA or property management company directly. A key fob deactivation is handled at the building level, not by a locksmith. Most San Diego HOAs can deactivate a fob within one to two business days on a written request. If your building uses key cards, the process is the same. Your front door rekey doesn’t cover building-wide access points.
Do I need to do anything about the garage if a roommate moves out?
Yes. If your building or home has a keypad garage entry, change the code immediately. This is the most overlooked access point after a roommate departs. It takes about 30 seconds and costs nothing. If your garage uses a remote transmitter, those can be deactivated through the garage opener’s programming menu, which typically involves holding a reset button.
How quickly can a locksmith come out in San Diego?
Same-day service is available most weekdays across San Diego County. If you call Swift Key San Diego at (858) 925-5546 before noon, the job is usually completed the same afternoon. Evening and weekend appointments are available with advance scheduling.
Roommate just moved out? Swift Key San Diego does mobile rekey service across every city in San Diego County. Same-day availability most weekdays. Call (858) 925-5546 to schedule.