How to Install a Smart Lock (2026 Guide)

If you’re wondering how to install a smart lock yourself, the good news is that on a door that already has a deadbolt it’s a 15 to 30 minute job with a Phillips screwdriver. There’s no wiring: the lock runs on batteries and fits the same holes your old deadbolt uses.

Whether it works well for years is mostly decided before you take anything apart: the door has to fit the lock, and the old deadbolt has to lock without you pushing or lifting the door. This guide covers those checks first, then the installation itself, step by step.

The quick version

Here’s how to install a smart lock in eight steps:

1. Check your door’s measurements and make sure the old deadbolt locks smoothly.
2. Remove the old deadbolt, both halves, plus the bolt and the strike plate.
3. Fit the new bolt in the edge of the door and the new strike plate in the frame.
4. Mount the outside half, with its cable routed under the bolt.
5. Mount the inside half and connect the cable.
6. With the door open, check that the thumbturn and key move the bolt smoothly.
7. Put the batteries in and let the lock calibrate itself.
8. Finish setup in the app, then test everything with the door shut.

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Replacement or retrofit: know which install you’re doing

Smart locks come in two types, and the installation is different for each.

A replacement smart deadbolt swaps your whole deadbolt, inside and out. You get a new exterior with a keypad, fingerprint reader or new keyway, and your old keys stop working. Most keypad smart locks, including the Schlage Encode Plus and Yale Assure Lock 2, work this way. The steps in this guide are written for this type.

A retrofit smart lock replaces only the inside part, usually the thumbturn. The outside of the door stays the same and your existing keys keep working. Level Bolt, Yale Approach and SwitchBot’s locks are retrofits. They’re the natural choice if you rent, although it’s still worth checking your lease first. There’s a short section on retrofit installs further down.

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Check your door first

Most smart deadbolts fit a standard US door prep. Measure yours before you buy:

• Face bore: the big hole through the door is 2-1/8 inches across.
• Edge bore: the hole in the edge of the door, where the bolt sits, is 1 inch.
• Backset: the distance from the edge of the door to the center of the big hole is 2-3/8 or 2-3/4 inches. Most smart locks come with a bolt that adjusts to either.
• Door thickness: usually 1-3/8 to 1-3/4 inches. Thicker doors need a kit (Schlage sells a thick door kit for its Encode locks on doors from 1-7/8 to 2-1/2 inches).

Then do the alignment test, which matters more than any measurement. Close the door and lock the old deadbolt. It should turn without you lifting, pulling or pushing the door, and the bolt should slide a full inch into the frame. If you have to lean on the door to lock it, a motor won’t manage it either. Fix the strike plate or the door before you install anything.

A few doors need more than a screwdriver:

• No deadbolt hole at all. You’ll need to drill the 2-1/8 and 1 inch holes with a door lock installation kit (a jig plus two hole saws) or have a locksmith do it.
• Mortise locks, Euro cylinders and handlesets. These aren’t the standard bored deadbolt most smart locks are made for. Check the lock maker’s compatibility list before you buy.

Finally, think about the connection. Wi-Fi locks such as the Schlage Encode Plus connect only to 2.4 GHz Wi-Fi. Many other locks talk to a small bridge or hub instead, so plan for an outlet within about 30 feet of the door.

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What you need

• A Phillips screwdriver (a hand screwdriver, not a power drill)
• A tape measure
• Everything in the box, including the template and the longer strike screws
• A pencil
• Fresh AA alkaline batteries, if the lock doesn’t include them
• Your phone, with the lock maker’s app installed
• A drill and chisel, only if the holes or the strike pocket need enlarging

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How to install a smart lock, step by step

These steps cover most replacement smart deadbolts. The order is the same across brands, but follow your lock’s guide for the exact parts. Keep the door open while you fit the parts.

1. Remove the old deadbolt

Unscrew the two screws on the inside part of the old deadbolt, then pull both halves off the door. Remove the screws holding the bolt in the edge of the door and slide it out, then take the strike plate off the frame. Keep the old lock until the new one is working.

2. Fit the new bolt and strike plate

Set the new bolt to your backset, then slide it into the edge of the door the right way up. Yale marks its bolt with an “UP” arrow, and Schlage asks you to center the slot in the bolt in the big hole. Screw it in so the faceplate sits flush.

Next, fit the new strike plate in the frame. If the box includes long screws or a strike reinforcer, use them: in Consumer Reports’ testing, a strong strike with 2-inch screws made every lock much harder to kick in, while short 1-inch screws make a door easier to force.

3. Mount the outside half

Feed the outside half’s tailpiece (the flat bar at the back) through the bolt mechanism and hold the unit flat against the door. Route its cable under the bolt, not over it, and make sure it isn’t pinched between the lock and the door. Yale’s installation guide calls this out specifically.

4. Mount the inside half

Fit the inside mounting plate over the tailpiece and screw it on. On most locks these screws pass through the door into the outside half, which holds both sides in place. Then plug the cable into the inside unit and fit the unit onto the plate. Use a hand screwdriver here, since Schlage warns that a power drill can damage the lock, and tighten the screws until they’re snug.

5. Test by hand with the door open

Before any batteries go in, turn the thumbturn and use the key (if your lock has one). The bolt should slide all the way out and back without catching. If it rubs, recheck the backset, the tailpiece orientation and the cable before going further.

6. Add the batteries and let it calibrate

Put the batteries in only when your lock’s guide tells you to. The lock then runs a calibration (sometimes called door handing), moving the bolt to learn which way your door opens. Do exactly what your lock asks here, because brands differ:

• Schlage and Kwikset run it with the door open.
• Google’s Nest × Yale wants the lock unlocked while the batteries go in, then asks you to close the door so it can calibrate.

Use the battery type the maker specifies. Schlage says its locks aren’t compatible with lithium batteries, and Kwikset recommends alkaline because rechargeables make the battery level read wrong, so you can miss the low-battery warning.

7. Set up in the app

Finish in the lock maker’s app, which adds the lock to your account and walks you through the settings. If your lock supports Apple Home, you add it in the Home app by scanning its setup code, and a lock that supports home keys puts one in Apple Wallet for everyone in the household. Matter locks come with a QR code and a pairing code: take a photo of both, because you’ll need them again after a reset.

Then close the door and test the lock every way you plan to use it: app, keypad, key and thumbturn. Turn on auto-lock last. If your lock has a door sensor, such as Yale’s DoorSense, set it up so auto-lock only fires when the door is actually shut.

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Installing a retrofit lock

A retrofit smart lock installation is shorter. Leave the outside of the deadbolt alone and remove only the inside thumbturn, which is usually held by two screws. Fit the adapter that matches your tailpiece, mount the new plate and attach the lock, then calibrate it in the app. Your existing key still works from outside.

Level Bolt works differently: it replaces the bolt inside the door, and you put your existing inside and outside parts back on over it (it comes with three adapters to match different deadbolts).

Some retrofits, like SwitchBot’s, don’t use screws at all: they clamp over your thumbturn and stick to the door with adhesive. Clean the surface first, and check that there’s enough clearance between the lock and the door frame.

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If it doesn’t work

If something’s wrong after the smart lock installation, check the door before the electronics:

• The lock grinds, stalls or reports a jam. Test it with the door open. If the bolt moves smoothly open but jams with the door shut, the strike plate is out of line. Rub a marker on the end of the bolt, close the door and turn it, and the mark shows where it hits. Enlarge the strike opening or move the plate. If it grinds even with the door open, rerun the calibration (Yale has a “Lock Handing” setting for this).
• The app can’t find the lock, or it shows offline. Stand at the door with Bluetooth on, check the Wi-Fi is 2.4 GHz, and move the bridge closer. For more fixes, see why a smart lock won’t connect.
• The batteries drain fast. A bolt that rubs makes the motor work harder every time. Fix the alignment, and use the batteries the maker specifies.

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The bottom line

Knowing how to install a smart lock is mostly about the order: check the door first, put the batteries in last, and do what your lock asks when it calibrates. With a door that locks smoothly, it’s a short screwdriver job. If you haven’t chosen a lock yet, start with the best smart locks for your door and your phone.