Rekey Locks Between Tenants? The Case for Every Turnover
Quick Answer: For most rental units, rekeying the locks at every tenant turnover is the sound default. It cancels every key the previous occupant, their guests, and their contractors ever had, and it costs far less than replacing hardware. Replace instead of rekey only when the lock is worn, damaged, or you are upgrading to a higher-security or electronic system.
A rental key is not a single object. It is a small population that grows quietly over a lease. A tenant makes a spare for a partner, another for a dog walker, one for the in-laws who visit at holidays. A handyman borrows a copy and forgets to give it back. By the time someone hands the keys back at move-out, the ring in your palm is only the copies they remembered to return. That gap between "keys returned" and "keys that exist" is the whole reason turnover is the moment to act.
What Rekeying Actually Does
Rekeying changes the inside of the lock so old keys stop working, without swapping out the lock itself. A standard pin-tumbler deadbolt or knob holds a stack of small spring-loaded pins in the cylinder. When the correct key slides in, its cut edge pushes each pin to a precise height so the cylinder can turn. A locksmith removes the cylinder, takes out the old pins, and drops in a new combination of pin heights matched to a fresh key. The old key no longer lifts the pins to the right line, so it spins uselessly.
The visible hardware- the deadbolt, the strike plate, the finish on the door- all stay exactly as they were. Only the internal code changes. Because nothing is replaced except a handful of small brass pins, rekeying is quick and far cheaper than buying and installing a new lockset.
Rekeying is different from a full lock replacement, where the entire mechanism comes off the door, and a new one goes on. Replacement is the right call when the hardware itself is the problem: a sticking bolt, a worn cylinder, a cracked housing, or a security grade you have outgrown. Rekeying assumes the lock is sound and only its key needs to change.
Master-key systems are a third option: A master-key system is a keying arrangement, not a brand of lock. A locksmith sets each cylinder so it accepts both the tenant's individual key and a single master key that opens every unit in a building. That lets a landlord or property manager carry one key for emergency access while each tenant still has a key unique to their own door. It adds convenience for multi-unit properties, though it also means the master must be guarded carefully, since losing it compromises the whole set.
Why Every Turnover Is the Moment That Matters
You can count the keys returned at move-out. You cannot count the keys that were made. That asymmetry is the core problem. A hardware store cuts a duplicate in under a minute for a few dollars, no permission asked, and nobody logs it. Over a year or two of tenancy, copies spread to people you never met: a subletter, an ex-partner, a house cleaner, a contractor who let himself in to fix a leak.
None of those people are necessarily a threat. The point is that you have no way to know they are not, and no way to retrieve keys you were never told about. The only reliable way to guarantee that no prior key opens the door is to change what the key has to match. Rekeying does that in one visit. Collecting keys, however diligently, never can, because you are trying to recover objects you cannot enumerate.
Turnover concentrates this into a single clean moment. The old occupant is out, the new one is not yet in, and the unit sits briefly under nobody's key. Doing the rekey in that window means the incoming tenant is the first and only person holding a working key from day one.
The Security and Liability Reasoning for Landlords
Think of the door lock as a password you inherited from a stranger, one that other strangers may also know. In software, you would never hand a new user an account whose password had been shared around by the last user and their friends. You would reset it. Rekeying is that reset for a physical door.
There is a duty-of-care dimension too. A landlord who hands a tenant a unit whose locks were never changed is giving them a door that may already be open to people from the last lease. If something goes wrong- an unexplained entry, a theft with no forced signs- questions follow about whether the locks were ever secured for the new occupant. Rekeying at turnover is a visible, defensible step that says the property was handed over clean.
Landlord obligations around lock changes vary by location, and some places have specific rules about when and how locks must be changed between tenancies. This article is general best practice, not legal advice. Check the requirements that apply where the property sits, or ask a local attorney or housing authority, rather than assuming a national rule exists.
Schedule the rekey during the vacant window, after the old tenant's final walkthrough and before the new tenant collects keys. That closes the gap entirely and makes the incoming tenant the first and only person holding a working key, without coordinating around anyone's furniture or schedule.
When Replacement Beats Rekeying
Rekeying assumes a healthy lock. Several situations tip the decision toward replacing the hardware instead.
The lock is worn or damaged: A deadbolt that sticks, a cylinder that grinds, a knob that wobbles, or a lock that has been forced or drilled in a past lockout is at the end of its life. Rekeying a failing lock re-codes a mechanism that is about to give you trouble. Replacement resets both the key and the reliability.
You are moving up in security: If you are going from a basic builder-grade lock to a higher-security cylinder, or adding features like anti-drill pins, hardened bolts, or a restricted keyway that stops casual duplication, that is a hardware change, not a rekey. The same is true for switching to an electronic or smart lock with codes you can change per tenant without touching the cylinder at all.
The keyways no longer match your plan: If you want several doors on a unit- front, back, and a garage side door- to open with one key, and the existing locks are a mismatched collection of brands and keyways, replacing them with compatible hardware makes keying alike clean and dependable.
Keying Multiple Doors Alike
Most single-family rentals and many units have more than one exterior door. A tenant who needs three separate keys for front, back, and garage tends to prop doors, hide spares, or leave one door off the latch. Keying alike solves that: a locksmith sets every exterior cylinder on the unit to the same combination so one key operates them all.
Keying alike happens at the same time as the turnover rekey, so there is no extra trip. The requirement is that the locks share a compatible keyway, which is why a mismatched set sometimes nudges you toward replacing a lock or two so everything can carry one key. The result is one key per tenant, changed cleanly at every move-out, across every door they need.
Frequently Asked Questions
A common residential deadbolt cylinder holds five or six pin stacks, and a rekey swaps the bottom pins in all of them to a new set of heights. A cylinder rekeyed to a fresh code has several possible combinations running into the thousands, which is why a random old key has effectively no chance of matching the new pinning.
Retail rekey kits exist for a few common brands and let an owner re-pin a lock at home. They work only on cylinders the kit is built for, demand steady hands with tiny springs and pins that are easy to lose, and give no help if a lock is a non-standard keyway or already worn. For a turnover you want verified across several doors, a locksmith re-pins them consistently and confirms each one before the new tenant arrives.
A fully electronic lock with no physical cylinder is not rekeyed at all; you simply delete the old codes or fobs and issue new ones. Many smart locks, though, keep a physical key override, and that override cylinder can and should be rekeyed at turnover so an old metal key cannot bypass the keypad.
The turnover rekey usually covers unit door locks, but a rental often comes with peripheral locks: a mailbox, a community gate fob, a padlock on a storage closet, a shared laundry room. These carry their own copies and are easy to forget. Note every keyed access point when a tenant leaves so nothing that opens a door or box is left on the previous lease's key.
Indefinitely. A cut key does not expire, wear out on a schedule, or deactivate when a lease ends. Unlike an electronic code you can revoke, a metal key keeps working for years until the lock it matches is rekeyed or replaced, which is why "they probably lost it by now" is not a security plan.
For a tenant renewing or returning to the same unit, there is no new population of unknown keyholders, so a rekey is optional rather than expected. The trigger for rekeying is a change in who holds keys, not the calendar. A renewal with the same occupants and the same returned spares generally does not need one, while any handoff to a new party does.
Book a turnover rekey while the unit is vacant — one key per tenant, every old copy retired. KwikPick Lock and Safe serves the Phoenix West Valley. Call (623) 300-1889.
