Short answer: yes. Every time I get this question from a new homeowner, I ask them one back — "Do you know exactly how many keys exist for this house, and who has them?" Nobody ever does. That's the whole reason to do it.
It's not about distrust of the previous owner. It's that a house accumulates key copies over the years in ways nobody tracks, and once you move in, you have no way to know how many are still floating around.
Who might still have a key you don't know about
- The previous owners — and anyone they gave a copy to over the years (family, a friend who watered plants, an adult kid who used to live there).
- Real estate agents who used a lockbox or held a key during showings.
- Contractors and repair crews — landscapers, pool guys, AC techs, anyone who was ever given access for a repair.
- Cleaning services that had a standing key for recurring visits.
- Former tenants, if the home was ever rented out.
- Home warranty or inspection companies that may have made a copy during due diligence.
Any one of those is probably harmless. But you have no way to know which ones are, which is the point — you're not protecting against a specific person, you're closing a door (literally) that you can't otherwise account for.
Rekey or full lock change — which do you need?
These get used interchangeably but they're different jobs:
- Rekeying changes the pins inside your existing lock so a new key is needed — every old key stops working instantly. You keep your current hardware; only the keys change. This is the faster, more affordable option, and it's usually all you need if the locks are in good working condition.
- A full lock change replaces the hardware itself. This is the right call if a lock is worn, damaged, doesn't match the rest of your doors, or you want to upgrade — for example, moving to a keypad or smart lock while you're already having a locksmith out.
If you're not sure which one your situation calls for, that's a normal question — we look at the hardware on-site and tell you honestly which one makes sense, not just the more expensive one.
Renting vs. owning
If you own the home, this is entirely your call and there's no reason to wait. If you're renting, talk to your landlord — many are fine with a rekey (not a full replacement) as long as they get a copy of the new key, and a good landlord understands why you're asking.
When to get it done
Ideally, before you move your belongings in — a locksmith can usually rekey a full set of exterior doors in under an hour, so it's easy to schedule right around closing or the day you get keys. If that's not possible, do it within the first few days. The point is to close that window as early as possible, not to feel like you have to rush it on move-in day itself.
What it actually costs
Rekeying is priced per lock and is typically the more affordable route when the hardware itself is fine — most homes need just their exterior doors done, not every interior lock. A full lock change costs more since you're paying for new hardware, but it's a one-time cost that also gets you newer, more secure locks if the old ones were dated. We quote every job upfront on-site, so you know the number before any work starts.