How to Rekey a Lock: A Complete Step-by-Step Guide for Homeowners

Learning how to rekey a lock is one of the most practical home security skills a homeowner can have. Rekeying changes the internal pin configuration of your lock cylinder so that old keys no longer work, without replacing the entire lock. Homeowners typically rekey their locks after moving into a new home, after losing a key, or after ending a relationship with a contractor, housecleaner, or tenant who held a copy. This guide walks you through the full process, explains what tools you need, and helps you decide when a DIY approach makes sense versus when a professional locksmith is the better choice.

What Does Rekeying a Lock Actually Mean?

A standard pin tumbler lock contains a series of spring-loaded pin stacks inside the cylinder. Each pin stack consists of a key pin and a driver pin. When you insert the correct key, its ridges push each key pin to exactly the right height, aligning all the driver pins at a single shear line. This alignment allows the cylinder to rotate and the lock to open.

When you rekey a lock, a locksmith or experienced DIYer removes the cylinder from the lock body, extracts the existing pin stacks, and replaces the key pins with a new set of pins that match a different key. The driver pins typically stay the same. The result is a lock that responds only to the new key and ignores all previous keys entirely. The hardware stays in place, the security level of the lock does not change, and only the key code changes.

Rekeying vs. Replacing a Lock: Which One Do You Actually Need?

Many homeowners assume they need a full lock replacement when rekeying is the better solution. Here is a direct comparison to help you decide:

In short, rekeying makes sense when your existing hardware is in good condition and you simply want to invalidate old keys. Lock replacement makes sense when you want better hardware, a different brand, or a smart lock with keyless entry.

Tools You Need to Rekey a Lock Yourself

Rekeying a pin tumbler lock at home requires a rekeying kit specific to your lock brand. Most major brands sell their own kits:

• Kwikset: Kwikset SmartKey Re-Key Kit (for SmartKey locks) or Kwikset standard rekeying kit
• Schlage: Schlage Rekey Kit (available online and at hardware stores)
• Defiant / Home Depot brand: Often uses standard Kwikset-compatible tooling

A standard rekeying kit typically includes:

You also need your current working key (to remove the cylinder) and the new key you want to use afterward. Note that Kwikset SmartKey locks use a completely different rekeying process that does not require disassembly at all.

How to Rekey a Lock: Step-by-Step

Follow these steps carefully. The process requires patience, especially when handling the small pin components.

Step 1: Remove the Lock Cylinder

Insert your current key and turn it 90 degrees. This aligns the cylinder for removal. Use the follower tool included in your rekeying kit to push the cylinder out of the lock body from the back. Keep the follower pressed firmly against the back of the cylinder as you pull it forward so that the driver pins and springs stay inside the lock body and do not scatter.

Step 2: Identify the Current Pin Configuration

Hold the cylinder over your pinning tray and use the key decoder (or measure with calipers) to identify the depth of each key cut on your existing key. Most standard locks have 5 or 6 pin chambers, each requiring a specific pin depth from 1 to 9 (or 0 to 9 depending on brand). Write down the pin depth sequence.

Step 3: Remove the Existing Key Pins

Insert the plug follower into the back of the cylinder to hold the driver pins in place. Then carefully tip the cylinder so that the key pins fall out into your pinning tray. Keep them in order in case you need to reference the original configuration. Do not lose the driver pins, as they remain in the lock body.

Step 4: Decode the New Key

Insert your new key into the cylinder and use the key decoder to read the depth of each cut. This tells you exactly which replacement key pins to use for each chamber. A deeper cut requires a longer pin; a shallower cut requires a shorter pin.

Step 5: Insert the New Key Pins

Using your pick tool, place the correct new key pin into each chamber according to the depth sequence of your new key. Work from the first chamber to the last. Make sure each pin drops fully into its chamber. Rushing this step causes the most DIY mistakes, so take your time.

Step 6: Reassemble and Test

Once all pins are in place, slide the cylinder back into the lock body, aligning the pins with the driver pins already inside. Remove the follower tool. Insert your new key, turn it, and confirm the lock operates smoothly. Then test that your old key no longer opens the lock. If the cylinder feels stiff or does not turn freely, a pin is likely misaligned and you need to disassemble and re-pin.

When to Rekey a Lock: The Most Common Scenarios

Here are the situations that most commonly call for rekeying rather than full replacement:

• After buying a home: Previous owners, real estate agents, and contractors may all hold copies of the key. Rekeying all exterior locks immediately after closing is the most cost-effective way to establish full control.
• After a tenant moves out: Landlords in Portland and the surrounding metro area typically rekey between every tenant. Oregon law does not specifically require it, but it limits liability and protects new tenants.
• After losing a key: If you cannot account for all copies of your key, rekeying costs far less than worrying about unauthorized entry.
• After a break-up or household change: Whenever someone who previously had a key to your home moves out or loses your trust, rekeying gives you a clean reset.

Should You Rekey Your Own Locks or Call a Professional?

DIY rekeying works well for homeowners who are comfortable with small parts and patient enough to follow detailed steps. However, several situations call for a professional locksmith:

• You own multiple locks and want them all keyed alike (matching one key to open all doors)
• Your locks are a brand or model you cannot find a rekeying kit for
• Your lock cylinder is damaged, worn, or stiff
• You dropped and lost any of the small pins during the process
• You want a security assessment alongside rekeying to see if your overall hardware is up to current standards

A professional locksmith can rekey most residential locks quickly and efficiently. If you are in the Portland area, Locksmith Near You provides residential locksmith services in Portland and the surrounding metro, including Beaverton, Hillsboro, and Lake Oswego. A professional visit also gives you an opportunity to assess whether your current hardware meets ANSI Grade 1 standards and whether any upgrades make sense for your home.

For additional guidance on residential security, the Associated Locksmiths of America (ALOA) maintains a library of homeowner security resources. Oregon requires all practicing locksmiths to hold a current license through the Oregon Construction Contractors Board (CCB).