Rekey or replace your locks? How to decide

What rekeying actually does

Inside a pin-tumbler lock there is a row of small pins cut to match one specific key. Rekeying means pulling the cylinder, swapping those pins to match a freshly cut key, and putting it back together. The lock looks identical, works identically, and every old key is now useless.

It takes about ten to fifteen minutes per lock, and while the locksmith is at it, locks of the same brand can usually be set to open with one key. Front, back, side gate and garage door on a single key is the single most popular request we get after a move.

What rekeying does not do is make a weak lock strong. Same cylinder, same bolt, same strike plate, same screws. If the hardware was the problem before, it is still the problem after.

When rekeying is the right call

Rekey when the lock is in good working order and the only thing wrong is who has a key.

• You just moved in. Previous tenants, cleaners, contractors and an unknown number of copies. Nobody rekeys before handing over, so assume it was never done.
• A key is lost, stolen or never came back. Especially if it was on a ring with anything that shows your address. If the loss also has you standing outside, the lockout guide covers the next twenty minutes.
• Someone moved out. A roommate, a partner, an employee, a tenant. Rekeying is cheaper and quicker than replacing and avoids the conversation about returning keys.
• You own or manage rentals. Turnover rekeys between tenants are standard practice, and in a busy rental neighborhood like PB they are the biggest share of our residential work.
• You want one key for every door. Keying alike is a rekey, not a replacement, as long as the locks share a brand and keyway.

When replacing wins

Replace when the hardware itself is the weak point, or when you want something the old lock cannot do.

• It is worn, sticky or corroded. Two blocks from the ocean, plated locks pit and seize in a few years. Rekeying a corroded cylinder is money spent on a lock that is about to fail anyway. Our coastal hardware guide covers what to buy instead.
• It is builder-grade. Light knob locks and thin deadbolts that came with the door. Rekeying keeps them light.
• There is no deadbolt. A knob lock alone is not a locked door. Adding a deadbolt is an installation, including boring the door if needed.
• You want a smart lock or keypad. There is no rekey path to a keypad; the hardware changes.
• The brands do not match. If you want one key for every door and the locks are three different keyways, at least some of them get replaced so the rest can be keyed alike.
• It is broken. A spinning cylinder, a bolt that will not throw, a snapped tailpiece. Sometimes repairable, often not worth it.

Keying alike, master keys and SmartKey

Keyed alike

Locks of the same brand and keyway can be pinned to one key. Mixed brands cannot, which is why a whole-house rekey sometimes includes swapping one odd lock so the rest can match.

Master keys

For a duplex, a small building or a business, a master key system lets each door have its own key while one key opens everything. That is a rekey with more planning, and it is the normal setup for landlords and commercial accounts.

Kwikset SmartKey

SmartKey cylinders can be rekeyed in seconds with a working key and the reset tool, no disassembly. The catch is the word "working": if the only key is lost, the cylinder has to be reset with a special tool, which is a locksmith job rather than a do-it-yourself one. Worth knowing before you count on doing it at the kitchen table.

Lock grades, in one paragraph

Residential locks carry an ANSI/BHMA grade from 3 (basic) to 1 (heaviest duty). The grade measures durability and strength, how many cycles the lock survives and how much force the bolt takes, not how hard it is to pick. So a Grade 1 deadbolt is not automatically pick-resistant, and a pick-resistant cylinder can sit in a Grade 3 body. For a front door near the beach the sensible target is a Grade 1 or 2 deadbolt in a corrosion-resistant finish, with a reinforced strike plate and long screws into the framing. That combination does more for security than any single feature on the box.

A decision checklist

Go down the list. The first "yes" is usually your answer.

• Lock is broken, spinning, seized or visibly corroded: replace.
• You want a deadbolt where there is none, or a keypad or smart lock: replace (install).
• Lock works fine and you just need old keys dead: rekey.
• You want one key for several same-brand locks: rekey (keyed alike).
• Locks are mixed brands and you want one key: replace the odd ones, rekey the rest.
• Not sure what you have: text us a photo. Honest answer, no visit needed.

On cost, the logic is simple even though the numbers vary by job: rekeying is labor only, replacing is hardware plus labor, and a rekey on a lock that is about to fail is the one option that costs money twice. More on how quotes work in the pricing questions.

Questions people ask