Every tenant turnover brings the same question, usually at the worst possible moment: do you change the locks, or just rekey them? Landlords get told confidently to do both, by different people, and the honest answer depends on things that have nothing to do with the lock itself.

Here is the distinction, and the situations where each one is actually the right call.

What rekeying actually is

Rekeying keeps the lock body and changes what key operates it. A locksmith takes the cylinder apart, swaps the pin stack to a new combination, and cuts new keys. The hardware on the door stays exactly as it was. From the outside nothing looks different.

The appeal is obvious. The lock, the finish and the fit all stay the same, and you are paying for labour and a small set of parts rather than new hardware. On a building with several units using the same brand of lock, rekeying also lets you keep a master key system intact.

What rekeying does not fix

Rekeying addresses one risk: people holding old keys. It does nothing about a worn cylinder, a sticking latch, a loose handle or a door that has to be shouldered to lock. If a tenant complained about the lock being stiff, rekeying hands the next tenant the same stiff lock with a different key.

When replacement is the better answer

Several situations make replacement the sensible choice rather than the expensive one.

The lock is worn out

Cylinders wear. After years of use the pins and springs lose their crispness, keys start needing a wiggle, and eventually one snaps off in the keyway. A worn cylinder can be rekeyed, but you are rekeying a part that is near the end of its life.

You do not know the key history

On a unit you have just bought, or one where keys were handed out to contractors and cleaners over several years, you do not actually know how many keys exist or whether any were copied. Rekeying solves that too — but if the hardware is also old, replacing gives you a known starting point.

The lock grade is wrong for the door

Residential-grade hardware on an entry door that gets used like a commercial one will keep failing. Builder-grade locks on rental units are a common false economy, because the replacement cycle is short and every failure is a call-out.

There was a break-in or an attempted one

After a forced entry the cylinder is rarely the only casualty. The strike, the jamb and sometimes the door edge take damage that is easy to miss. Rekeying a lock mounted in a split jamb leaves a door that looks secure and is not, which is why a break-in is a case for looking at the whole opening through residential door repair rather than just changing what the key does.

The thing most landlords miss: the door, not the lock

A surprising share of lock complaints are not lock faults. If a door has dropped on its hinges or the frame has shifted, the latch no longer lines up with the strike. The tenant has to lift or lean on the door to get the deadbolt to throw. They report a bad lock, and a new lock gets fitted into the same misalignment.

The test is quick. Open the door, throw the deadbolt into the air, and check it extends smoothly and fully. If it does, the lock is fine and the alignment is the problem. If it binds with the door open, the lock itself needs attention.

The same logic applies to a door that will not stay shut without being pulled. That is a latch and strike geometry issue, and no amount of rekeying touches it.

A turnover checklist that prevents repeat calls

Doing these in order between tenants catches most of what otherwise comes back as a mid-tenancy emergency:

1. Check the deadbolt throws fully with the door open. This separates lock faults from alignment faults.
2. Check the strike plate screws. Short screws into soft trim are the single weakest point on most entry doors. Long screws into the stud frame cost almost nothing.
3. Look at the hinge screws. Loose top hinge screws are the start of every sagging door.
4. Test the latch without the deadbolt. If it needs a pull to catch, the strike needs adjusting.
5. Then decide rekey or replace. By this point you know whether you are dealing with hardware at the end of its life or hardware that is fine.
6. Record the key count. Write down how many keys were cut and handed over. This is what makes the next turnover simple.

If step one or four turns up a door that is out of alignment, that is the work to book first. Doors that have moved enough to affect the lock usually need hinge, frame or strike work, and on older units it sometimes makes more sense to look at replacing the entrance door than to keep adjusting a slab that has warped.

Multi-unit buildings add a wrinkle

In a building with a master key system, swapping one unit’s lock for a different brand breaks the system for that door. You now have a unit that the master key does not open, which matters for access during an emergency.

If you are replacing hardware in a mastered building, the replacement has to be keyed into the existing system, which means matching the keyway. That is a specification question before it is a purchasing question. On new units or a building being set up from scratch, getting the hardware consistent from the start through planned door installation saves years of mismatched cylinders.

Frequently asked questions

Is rekeying as secure as replacing the lock?

For the specific risk of old keys, yes — a rekeyed cylinder cannot be opened by the previous key. What rekeying does not improve is the mechanical condition or the grade of the lock.

Do I have to change locks between tenants?

Requirements vary by jurisdiction and by what your lease says, so that is worth checking against your own obligations. As a practical matter, most landlords rekey or replace at every turnover because the alternative is trusting that no copies exist.

Can all locks be rekeyed?

Most pin-tumbler locks can. Some low-cost locks and some high-security systems are exceptions, and a cylinder that is already worn or damaged is not a good candidate.

The tenant says the key sticks. Is that the lock?

It can be a worn cylinder, a bent key, or a door out of alignment putting side pressure on the bolt. Testing the deadbolt with the door open tells you which.

Should I upgrade to a keypad lock for rentals?

Keypad locks remove the key-copying problem and make turnovers quick, since you change a code instead of a cylinder. They add batteries and electronics to maintain, so the trade is convenience against another thing that can fail.

The short answer

Rekey when the hardware is sound and you only need to invalidate old keys. Replace when the lock is worn, the grade is wrong for how the door gets used, or there has been a forced entry. And before doing either, check that the door and strike are aligned — because that is what causes most of the lock complaints that rekeying will not fix.