Rekey vs. replace locks: which do you need?

When you want to control who can get into your home or business, you have two main options: rekey the locks you have or replace them with new ones. Both make old keys stop working, but they solve different problems. Here’s how to decide which one fits your situation.

What rekeying and replacing actually mean

Most residential locks are pin tumbler locks. Inside the cylinder is a row of spring-loaded pin stacks, and each key lifts those pins to exactly the right height so the cylinder can turn. Rekeying means removing the cylinder, taking out the old bottom pins and installing new ones that match a different key.

The lock looks exactly the same from the outside. The handles, finish and deadbolt stay in place. The only change is which key works, and the old keys stop working immediately.

Replacing a lock means removing the old hardware and installing a new lock body, cylinder, latch or bolt and strike. It comes with new keys, but it also gives you a chance to change the lock’s strength, style or function.

Replacement takes more time and costs more because you’re paying for hardware as well as labor. In return, you get a lock that can do things the old one couldn’t.

When rekeying is the better choice

Rekeying is the right call when your locks work well and you’re happy with them, but you’re not sure who has copies of the key.

• You just moved into a new or resale home
• Keys were lost or stolen
• A roommate, tenant or former partner moved out
• Contractors, cleaners or dog walkers had keys
• You want every door to work with one key and the locks are compatible
• You’re turning over a rental between tenants

When replacing is worth it

Replacement makes more sense when the problem is the hardware, not the keys.

• The lock is worn, loose, sticky or hard to turn
• It was damaged in a break-in or attempted forced entry
• You want a stronger deadbolt, such as moving from Grade 3 to Grade 2 or Grade 1
• You want keyless entry, a keypad or a smart lock
• The lock is a style that can’t be rekeyed
• You’re updating the look of your doors

Cost and time, in plain terms

Rekeying is almost always the less expensive option. You pay for labor, pins and new keys, and a typical cylinder takes only minutes once the locksmith is set up. Doing a whole house in one visit is common.

Replacement costs more because of the hardware, and the price depends heavily on what you choose. A basic deadbolt is inexpensive; a high-security or smart lock costs more. Installation also takes longer, especially if the door needs adjustment. A sensible approach for many homes is to replace only the locks that need upgrading, usually the front door and garage entry, and rekey the rest to match.

Moving into a new home

Whether the house is brand new or decades old, you have no way of knowing how many keys are floating around. Builders, subcontractors, real estate agents, previous owners, their relatives and their dog walkers may all have had copies.

Rekeying every exterior lock on move-in day is one of the most cost-effective security steps you can take. While the locksmith is there, it’s also a good time to check that the front deadbolt is solid, the strike plate uses long screws and the sliding door locks properly.

Many smart locks and keypad deadbolts still have a keyed backup cylinder. When you move into a home with one, reset it to factory settings, delete old codes and user accounts, and rekey the backup cylinder. Otherwise, a previous owner may still have a code or a key.

If you’re adding a smart lock to a door that currently has a standard deadbolt, that’s a replacement, and the new lock’s backup cylinder can usually be rekeyed to match the rest of your house.

Master keying for rentals and businesses

If you manage rental units or run a business, you might want a master key system. Each unit or office has its own key, and the owner or manager has one master key that opens all of them.

Master keying is done by rekeying the locks with extra pins that create two valid key combinations. It takes planning because every lock in the system is related. It’s also a good time to consider restricted keys, which can’t be copied at a hardware store, so you stay in control of how many keys exist.

Lost or stolen keys

How urgently you act depends on what was lost with the keys. A single key dropped somewhere with nothing identifying it is lower risk. A full key ring stolen along with a wallet, a car with a registration in the glovebox, or a bag with your address in it is different, because whoever has the keys may also know where they fit.

In the second case, rekey the exterior locks the same day. Rekeying works just as well as replacement for this purpose and is quicker to arrange. If the car key was taken too, ask whether the lost key can be erased from your vehicle’s memory when a new one is programmed.

A quick way to decide

Ask yourself two questions. Does the lock work well and do what you need? If yes, rekey. Is the lock worn, damaged, weak or missing a feature you want? If yes, replace it.

If you’re unsure, a locksmith can look at your locks and tell you which ones are fine to rekey and which are worth replacing. If you’d like help finding one, we can connect you with an independent, licensed locksmith who serves Fresno. The referral is free.

Common questions