The problem with renting is not that smart locks are hard to install. It is that the door is not yours, and most of the advice written about smart locks quietly assumes it is.
So the question worth answering is not which lock is best. It is which lock leaves the door exactly as you found it. Once you filter for that, the list gets short and the decision gets easy.
The test that matters
Before looking at a single product, hold it against three questions.
- Does anything change on the outside of the door? If a neighbour or the building manager can see that something is different, you have changed the door.
- Does the landlord’s key still work, exactly as before? If their key stops opening the unit, you have almost certainly broken your lease, and in many places you have also broken a legal obligation to allow lawful access.
- Can you put it back to original in fifteen minutes, with no filler, no paint, and no new holes? If not, it needs written permission first.
Anything that passes all three you can generally fit on a Saturday morning without telling anyone. Anything that fails one is a conversation with the landlord, not a purchase decision.
The option that actually works: retrofit over the existing deadbolt
A retrofit smart lock replaces the thumbturn on the inside of your door and nothing else. The exterior cylinder stays. The deadbolt stays. The keys stay. From the hallway your door looks identical, because it is identical. August and SwitchBot are the two names most people end up with here, and both mount with the screws that were already holding the thumbturn on.
This is the whole answer for most renters, and it is worth understanding why it works so well rather than just taking the recommendation. Everything a landlord cares about lives on the outside of the door and in the lock cylinder. A retrofit lock touches neither. You are adding a motor to the inside of your own apartment, in the same way you might add a lamp.
What you get: phone unlocking, auto lock behind you, temporary access for a friend or a dog walker, and a log of when the door opened. What you do not get: a keypad on the outside. Nobody can punch in a code at your door, because there is nothing out there to punch it into. If keyless entry from the outside is the point, see the section on keypads below.
One warning that applies to every retrofit lock, and it comes up constantly in complaints: the motor inherits your existing deadbolt. If that bolt sticks, or needs the door pulled towards you before it turns, the lock will struggle and eventually stall. Test it by hand with the door closed before you buy. If it is stiff, ask the building to adjust the strike plate, which is maintenance they generally owe you anyway. Our installation guide covers how to check and fix that alignment.
Keypad locks: possible, but ask first
A keypad or fingerprint lock means replacing the entire deadbolt, inside and out. The old lock comes off, a new one goes on, and the landlord’s key no longer opens your door.
This is not automatically forbidden. Plenty of landlords say yes, especially smaller ones, and especially if you ask properly. But it is a permission question, not a hardware question, and doing it quietly is how people lose deposits.
If you want to ask, the version that tends to work is specific rather than enthusiastic. Something close to: the existing deadbolt comes out intact and gets stored in the closet, the new lock uses the same holes and needs no drilling, the landlord gets a permanent access code plus a physical key if the model has a keyway, you pay for it, and the original lock goes back on the week you move out. Landlords say no to vague requests about smart home upgrades. They say yes far more often to a reversible swap with their own access preserved.
Get the answer in writing, even if it is only an email reply saying fine. That email is the thing that protects your deposit two years later when the property changes hands.
What not to do
Some things are not worth the risk on a door you do not own.
Drilling a new bore. If your door has no deadbolt hole, adding one is permanent damage to someone else’s property. It is also the one mistake you cannot undo cheaply. Do not.
Rekeying or replacing the exterior cylinder. Even where it is technically legal, it takes away the landlord’s lawful access and it is the fastest way to turn a small disagreement into a lease violation.
Fire rated doors. Many apartment entry doors are fire rated, and cutting or drilling one voids the rating. That moves you from a deposit dispute into a liability problem. Look for a metal label on the hinge edge of the door. If you see one, do not modify the door at all, and stick to retrofit.
Shared entrances. The building’s front door, the lobby, the parking gate. None of that is yours to change, whatever the state of your own front door.
Apartment doors have their own problems
A house door and an apartment door are not the same object, and the differences catch people out.
Metal doors and narrow stiles. Many apartment entry doors are hollow metal, and some have a narrow strip of frame around the lock. Big round smart lock bodies sometimes foul the door frame or the weather seal. Measure the space between the deadbolt and the door edge, and between the deadbolt and the handle below it, before ordering.
Wi-Fi that does not reach the door. Your entry door is often the furthest point in the apartment from your router, sitting behind a metal door in a concrete hallway. Locks that need Wi-Fi at the lock itself struggle here. Locks that use Bluetooth plus a bridge you can plug in nearby, or Thread and Matter through a hub, tend to do better. Which route you take depends on the ecosystem you already use, and our guide to smart locks that work with Google Home goes through what each option needs.
Deadbolts that were never adjusted properly. In buildings with dozens of identical doors, alignment gets ignored for years. This is the single biggest cause of retrofit locks failing in apartments. Fix it before you fit anything, and ask the building to do it if you can.
You may not be the only one with a key. Building staff, the previous tenant’s cousin, a lockbox from a viewing months ago. A smart lock with an access log will not stop any of that, but it will tell you it happened, which is more than a mechanical lock does.
Short term lets and shared houses
If you are hosting rather than renting, or you are the one handing out access, the priorities flip. What matters is issuing and revoking codes without meeting anyone, which needs a keypad on the outside and therefore usually needs a lock you own the right to change. That is a different setup, and one worth planning around the door you are allowed to modify rather than the one you wish you had.
In a shared house, the usual friction is not the front door but the individual room doors, which are typically interior privacy locks with no deadbolt at all. Most smart locks do not fit those. Fitting one usually means new hardware and permission, which brings you back to the same conversation.
The moving out part
Whatever you fit, plan the removal on the day you fit it.
- Keep the original hardware, screws included, in a labelled bag. Not in a drawer with everything else. The screws are the part people lose.
- Photograph the door before you touch it, so you know what original looked like.
- If you replaced the deadbolt, put the old one back yourself rather than leaving the new one as a gift. Landlords do not want to inherit a lock tied to your account, and an account you forget to delete is a genuine security problem for the next tenant.
- Factory reset the lock and remove it from your app before it leaves your possession, whether it goes back in a box or gets sold.
Common questions
Can my landlord say no to a retrofit lock?
They can object to almost anything, but the case is much weaker when nothing about the door has changed and their key still works. This is why the interior only option is the one to reach for. If your lease has a broad clause about alterations, read it before assuming either way, and remember that rules vary by state and by country.
Do I have to tell my landlord?
For an interior thumbturn swap with no visible change and no effect on their access, most people do not, and most leases do not require it. For anything that changes the exterior or the cylinder, yes, and get it in writing. If you are unsure which category you are in, the three questions at the top of this article are the test.
What if the lock dies while I am out?
With a retrofit lock, nothing happens to your access. The original cylinder and your original keys are untouched, so you unlock the door the way you always did. That resilience is a real advantage of this design and not just a technicality. With a full keypad replacement, check whether the model has a keyway or emergency battery contacts before you buy.
Is it worth it for a one year lease?
A retrofit lock comes off in ten minutes and goes on your next door, so the cost follows you rather than staying with the apartment. That is the practical argument for choosing reversible hardware even when you could get permission for something more permanent.
The short version
If you rent, start with a retrofit lock that only replaces the interior thumbturn. It leaves the outside of the door untouched, keeps the landlord’s key working, and comes off without a trace. Anything beyond that is a permission conversation, and it should happen by email before it happens with a screwdriver.