Rekey Locks: How Many Locks, What a Key Set Means, and How to Plan

What rekeying actually changes

A pin tumbler lock, the common type on house doors, holds a column of small pins in the cylinder. Each pin has a different length. The right key lifts every pin to exactly the line where the cylinder can turn. A wrong key leaves at least one pin blocking the turn.

Rekeying replaces those pins with a new set cut to a different pattern. The cylinder stays in the door. The hardware around it stays put. Only the pins inside change, and a new key is cut to match them. The old key now lifts the pins to the wrong heights, and the lock will not turn for it.

That is the whole idea. The result is a lock that looks the same and works the same but answers to a different key. It costs less effort than replacing the lock and keeps hardware you may already like.

Rekeying is not a repair. If a lock is worn out, bent, or broken, new pins will not cure it. Our broken lock repair page covers those cases. Rekeying is for a lock that works well but whose keys you no longer trust.

When rekeying makes sense

The most common reason is a key that left your control. A lost ring, a stolen bag, a former tenant, a contractor who held a key for a month, a roommate who moved out, an ex partner. In each case the lock is sound but someone you do not choose may hold a working key.

Moving into a new home is the other big reason. You do not know how many copies of the old keys exist. Previous owners, their relatives, cleaners, neighbors and agents may each hold one. Rekeying on the day you move in resets that history to zero.

Another reason is convenience. Over years, a household collects a ring of keys that fit different doors. Rekeying lets several locks share one key, so you carry one key instead of four. Shops and small offices do the same for staff.

A final reason is tidiness after a lockout. If a night visit showed that a lock was in good shape but a key is missing, a rekey can follow. See our night house lockout page for how that often unfolds.

Step one of the plan: count the locks

Planning a rekey begins with a walk around the property. Count every lock that uses a key. Be thorough. People forget the less obvious ones.

Start with the exterior doors: front, back, side, patio, and any door from the garage to the yard. Then the door between the garage and the house. Then windows with key locks, if any. Then the garage side door. Then padlocks on gates, sheds, and storage. Then mailbox locks, if they are yours. Then cabinets, filing drawers, and a safe if its lock accepts a keyed cylinder. Many locks also come in pairs, such as a deadbolt above a handle set, and each one counts separately.

Write the list on paper. For each lock, note the door, the type, and whether the key works smoothly today. This list is the backbone of the plan. It also reveals problems. A lock that sticks should be flagged for repair before it is rekeyed.

A rough count is enough to request a visit. An exact count helps the locksmith bring the right number of pin sets and blank keys.

• Count every exterior door lock, including patio and side doors.
• Count the garage entry door and any shed or gate padlocks.
• Note deadbolts and handle sets on the same door as separate locks.
• Add keyed window locks, mailbox locks and cabinet locks if relevant.
• Flag any lock that sticks or feels loose for repair first.

What a key set means

A key set is a group of locks that all open with the same key. Planning a rekey means deciding what your sets should look like before work starts.

The simplest choice is one set for everything. One key opens the front door, back door, garage entry and shed. It is convenient, and it is a good fit for a household where everyone should reach every door. The cost is that losing the key exposes every door at once.

A split design uses two or more sets. Perhaps the front and back doors share one key, while the shed and the workshop share another. Each family member carries the key they need. This limits what any one lost key can open.

A third choice is a master key system, where each lock has its own key but one master key opens them all. That suits shops and small offices with several staff. We cover related ideas on the business door hardware page.

Think about people before locks. Who needs which door? Who needs access only sometimes? Who should never have a key again? Those answers shape the set.

Pin counts, keyways and what limits a rekey

Not every combination is possible. Some physical facts limit the plan, and a locksmith will explain them honestly.

Locks from one maker usually share a keyway, the shape of the slot in the cylinder. Locks from different makers have different keyways. A key only enters a lock whose keyway matches. To put two locks on one key, they often need the same keyway. If they do not, the options are to swap one cylinder for a matching one, or to keep separate keys.

Pin count matters too. A cylinder with five pins has more possible patterns than one with four, and some basic locks are limited. Heavier locks accept more combinations. A very worn cylinder may not hold new pins well, which is why we test the lock before and after.

Some hardware cannot be rekeyed. A lock may be built without a way to change the pins, or its parts may be too damaged. In that case the honest answer is replacement, and our install new locks page explains how that works.

How a rekey visit runs

A visit follows a steady order, which is calm and easy to watch. The team arrives in uniforms with a branded service van that holds professional tools, key cutting equipment, and common hardware.

First the locksmith confirms who you are and that you have authority over the property. A tenant should know what the landlord permits. Then they look at the first lock and confirm it can be rekeyed. The cylinder is removed from the door, which usually takes a few moments. Inside, the old pins are taken out and the new ones set according to the pattern for the new key.

The cylinder goes back into the lock. The new key is tested several times. The old key is tried too, and it should no longer turn. That test matters, because it proves the change worked. Then the locksmith moves to the next lock and repeats.

When all locks are done, you receive the new keys, and the locksmith checks that each key opens only what it should. Walk to each door and try your key. Watch the bolt throw fully and retract fully.

While the cylinder is out, a careful locksmith also looks at the hardware around it. Is the bolt sliding freely? Is the strike plate aligned, so the bolt meets its hole cleanly? Are the screws tight? A rekey is a natural moment to notice small faults, and mentioning them costs nothing. You decide whether to act on them today or later.

The old key test: confirming the rekey worked

The strongest proof of a rekey is an old key that fails. Ask to see it. Hold the old key and try it in each rekeyed lock. It should enter the lock but not turn. If any old key still turns a rekeyed lock, something was missed.

This test applies to every old key you can find. Spare keys in a drawer, the ring from the previous owner, the key you thought was lost. Give the locksmith the old keys, and try them all if you can.

Do not throw old keys away at once. Keep one, in a safe place, until a week or so has passed. A door that sticks once in a while is usually the work of a new key still settling in, but a hidden problem, like a lock that has become stiff, can show itself in the first days. A spare old key does not help you open the lock again, but it is worth keeping to show the locksmith if a question arises.

If you are not satisfied with how a lock feels, say so before the visit ends. A new key should enter smoothly, turn without force, and withdraw without catching. A key that feels gritty or tight on the first day deserves attention, because friction wears both key and pins.

Lubrication is a related question. Heavy oil attracts dust and can gum the pins over time, especially in the dry summer dust of the valley. A light dry graphite or a lock specific lubricant is usually the better choice. Ask the locksmith what they recommend for your type of lock and climate, including the cold of the mountain towns.

Planning for multiple doors, tenants and properties

A single house can be done in one visit. A bigger plan needs thought. An apartment building, a rental, or a small business with many doors can be organized in stages.

If you own several rentals, think about tenant turnover. Rekeying between tenants is common practice, and a clear routine makes it easy. Rules about who must rekey and when vary by place and by lease, so we cannot state them. Ask your management company or an advisor.

For a small business, think about staff. Who gets a key to the front door, who to the stock room, who to the office? Write the answers down. A rekey is the right moment to fix this.

For a home with several adult residents, decide who holds which key. Mark each key head or tag, so everyone knows. Decide who keeps the spare, and where.

If your plan involves new hardware at some doors and rekeying at others, mix them in one visit. The locksmith can match new locks to the existing set.

Doing it at night or in daylight

Rekeying is often a planned daytime job. It does not need to be urgent. A well planned visit costs less stress than an emergency one.

Sometimes it is urgent. A stolen bag with keys and your address inside, a break in, or a lost ring on a night out are all reasons to act at once. Our after hours emergency service covers that case, and the aim is to make the property secure that same night where practical. If a full rekey cannot be done in darkness, the locksmith can talk through the options, such as securing the most exposed doors first.

If the cause is a lost vehicle key that was on the same ring as a house key, see vehicle key replacement too. Both locks matter.

Local examples show how this applies on the ground. See rekey locks in Redding and rekey locks in Fort Jones. Our home locksmith page covers the wider residential service.

Keeping track of keys after the rekey

A rekey is only as strong as the habits that follow it. New keys can be lost as easily as old ones. Make a simple record of who holds which key, when it was handed over, and how many copies exist. A page in a notebook is enough.

Be careful with copies. A copy made at a counter by someone who does not know your plan can undo the careful set you built. Decide in advance who may order extra keys and where they will be cut. Keys stamped with a do not duplicate mark are a deterrent, not a lock, so do not treat them as proof against copying.

Do not label keys with your address. A tagged ring that is lost tells a stranger exactly which door to try. Use a color mark or a number that only your household understands.

Revisit the plan when life changes. A new roommate, a worker finishing a project, a child old enough to hold a key, or a teenager leaving for college each change who should have access. A rekey is easy to repeat, and it is better to adjust than to hope.

What to prepare and how to ask for a visit

Before the visit, have your lock count, your list of key holders, and your wishes for key sets ready. Collect all old keys. Make sure each door is reachable. Clear a path. Put pets in a quiet room.

Be ready to show that you live at or manage the property. Identification and proof of address are typical. Tenants should bring landlord approval, if their lease calls for it.

Tell us your area. We serve Redding, Anderson, Shasta Lake, Cottonwood, Palo Cedro, Millville, Lakehead and Sims in Shasta County, and Mount Shasta, Yreka, Dunsmuir, McCloud, Weed, Granada, Montague, Fort Jones and Etna in Siskiyou County. See the coverage pages for each community.

The request form is on our contact page. A phone line is coming soon, and no number is published now. Include the count of locks, the key sets you want, and whether any lock sticks. That is enough to start.

Common questions