When to rekey or change locks

The honest answer: it depends on who has keys

People often ask how often locks should be changed, as if there were a schedule like an oil change. There is not. A lock in good condition can serve for many years without any change. What matters is whether the group of people who can open it still matches the group you want. When those two groups differ, you have a reason to act, whatever the date.

This way of thinking makes the decision simpler. Instead of asking whether a certain time has passed, ask whether anything has changed about who has access, who might have copied a key or what condition the lock is in. If something has changed, rekey. If nothing has, leave it alone and keep your records tidy.

The sections below cover the common triggers. Some are obvious, such as a lost key. Others are quieter, such as a contractor who worked in your home for a month and was handed a key, or an ex-partner who kept one without anyone noticing.

Rekey or replace: what the difference means

Rekeying changes the inner pins of the lock cylinder so that a new key works and the old keys do not. The lock itself stays in the door. It is typically faster than replacing and uses the hardware you already have. Replacement means removing the lock and installing a new one, which makes sense when the lock is worn, damaged, low grade or you want a different type.

A useful rule is to rekey when the lock is sound and replace when the lock is the problem. If the lock turns smoothly, the bolt extends fully and the grade is acceptable, rekeying gives you the security reset you need. If the lock is loose, rusted, damaged or weak, a new lock fixes the underlying issue as well as the key question.

A technician can inspect each lock and tell you which route fits. You can read more on the pages for lock rekey service and lock change and installation.

After you move into a new place

When you move into a home or apartment, you cannot know how many keys exist. Previous residents, agents, family members, maintenance staff and neighbors may all have held one. Rekeying right away gives you a clean start, and it is usually worth doing even if the seller or landlord says all the keys were returned.

If you rent, ask your landlord whether a lock change is part of tenant turnover. Many places require it, and some leave it to the tenant to request. Do not change a lock yourself without permission, since the lease may require the landlord to hold keys. See apartment and landlord locksmith for how it works in rentals.

If you own, the new homeowner lock checklist walks through every entry point. The timing is simple: the sooner after you get the keys, the shorter the time during which unknown keys still work.

After a breakup or a change in the household

When a relationship ends, or a roommate moves out, keys can linger. Even with good intentions, a former partner may keep a key, forget to return it or have given a copy to someone else. Rekeying removes the question. It is not an accusation, only a practical step, much like changing a password after a shared account is no longer shared.

If there is any concern about safety, take the matter seriously and consider contacting local authorities or support services. Rekey promptly, and consider adding a deadbolt, checking the strike plates and securing sliding doors and windows. The rest of the security around the home matters too.

Remember to reset other forms of access. Garage opener remotes, keypad PINs, smart lock accounts and alarm PINs may also be known to the person who is leaving. Reset each of them, and change shared passwords for any connected devices. Keys are only one part of access.

After lost or stolen keys

A lost key that has your address on a tag or sits in a bag with your identification is a security problem. A stolen key is worse. Even a key you think you lost at home is uncertain, since you cannot be sure it will not turn up in the wrong place. If there is any real chance someone else has it, rekey.

If the key was lost far from home and has nothing linking it to you, the risk is lower, but it is still not zero. The question is how much risk you are comfortable with. For a home with valuable things or a family inside, many owners choose to rekey promptly. For a low-risk situation, they may decide to wait and watch.

For vehicles, lost keys are a similar issue. A technician can often remove the missing key from the car's memory so it cannot start the vehicle, which is the car equivalent of rekeying. See what to do when you lose your car key and stolen car keys.

After contractors, cleaners and other temporary access

Home improvement projects, long-term cleaning arrangements and house sitting all tend to involve handing out keys. It is easy to forget who still has one a year later. A contractor who worked for a few weeks may have made a copy for a helper. A house sitter may have given a spare to a friend.

A practical habit is to track every key you issue. When the job ends, ask for the key back, then decide whether it has been long enough or the access broad enough to warrant a rekey. If the work involved the whole house for many weeks, rekeying afterward is a sensible reset. If the contractor only used a gate or a single door, you may only need to change that one.

A temporary access option, such as a smart lock with an expiring PIN, avoids the problem. You issue a PIN for the duration of the job, and it ends on its own. Read about this on smart lock installation.

When employees or tenants leave

For a business or a rental, key control is a bigger task. Employees who leave, tenants who move out and former managers can all hold keys. A business should have a policy for returning keys and for rekeying when a person with broad access departs, especially when they leave on poor terms.

Keyed alike and master key systems can make this manageable. A master key system lets one key open many doors, while individual keys open only one. When a person leaves, the affected locks can be rekeyed without disturbing everything. The page on master key systems explains the idea, and key control basics for business owners offers a simple framework.

For landlords, the usual practice is to rekey at tenant turnover so that each tenant has a unique set. It protects both the tenant and the property, and it is easier to document.

Key sharing, copies and unknown duplicates

Over time, keys get shared, and sharing is how control erodes. A spare given to a neighbor, a key left with a relative, a copy cut at a kiosk for a friend: each one is a small, harmless act that adds up. After a few years, you may not know how many keys exist.

One solution is a restricted key system, where key blanks are controlled and copies need authorization. Another is rekeying periodically when you are not sure. If you cannot say with confidence how many keys exist, rekeying brings the number back to what you know. It is like resetting a shared Wi-Fi password when you cannot remember who has it.

Keep a simple list of who holds which key. You do not need anything elaborate. A note on your phone is enough. It lets you answer the question the next time it arises.

Signs the lock itself needs attention

Besides access changes, a lock can show signs that it needs rekeying or replacement. A key that is hard to insert, a cylinder that sticks, a bolt that does not extend fully or a handle that wobbles can all indicate wear or damage. Sometimes the key itself is worn and a fresh copy fixes the problem. See worn key symptoms for how worn keys behave.

Damage from an attempted break-in is another reason to act. Scratches, pry marks, a bent strike or a loose cylinder mean the lock may fail next time. The page on lock repair after a break-in describes what a technician will examine.

Environment matters too. Locks near the coast, in heavy weather or in harsh sun may corrode or wear faster. If a lock has been in poor condition for a long time, replacing it can be better than repeatedly repairing.

Vehicles, sheds, gates and the locks people forget

When people think about changing locks, they picture the front door. The list is longer. A detached garage, a storage shed, a gate, a mailbox, a utility cabinet, a toolbox and a boat or trailer all use keys, and any of them may have been handled by people you no longer want to have access. A shed full of tools is an easy target, and a trailer hitch lock is only useful if the key is not floating around.

Cars deserve the same thought. A used car often comes with a spare key from a previous owner, and a seller who kept one is something to consider. If you buy a used vehicle, ask whether all keys were handed over, and ask a technician whether the old keys can be removed from the car's memory so that only the keys you hold will start it. The page on spare car key programming explains how spare keys are added to a vehicle.

Garage door openers and keypad PINs also count as keys. If an opener has been in the house since before you arrived, clear its memory and set up only the remotes you use. If a keypad PIN was shared with a neighbor or a worker, change it. Treat every form of access the same way, and you will have a much clearer picture of who can get in.

A simple decision guide

Use the questions below to decide. If any of the first four apply, rekeying is generally appropriate. If the last two apply, consider replacement or a broader review.

• Have you moved in recently or taken over a property?
• Has someone with a key left the household or the business?
• Is a key lost, stolen or unaccounted for?
• Has anyone had long-term access and kept a key?
• Is the lock worn, loose or damaged?
• Was there an attempted break-in?

What happens when you call

A rekey is a short job. A technician checks each lock, rekeys the cylinders, cuts new keys and tests them. You should be home, or have a trusted person there, and be ready to show proof you control the property. Quotes are given by phone, and complicated jobs may need an on-site visit. The guide on how to prepare for a locksmith visit lists what to have ready.

If you are weighing whether a lock change is needed, call and describe what has changed. A technician will help you decide whether to rekey, replace or leave things as they are.

Questions people ask

Related pages

Written by Claude (AI) (AI) for 24/7 Locksmith USA.