What is a master key system, and who actually needs one in Van Nuys?
A master key system is a planned way of keying many locks so that different keys open different groups of doors. Every door still has its own individual key. On top of that, a higher-level key opens a defined set of those doors. A tenant's key opens one apartment. A building manager's key opens every apartment and the laundry room. The owner's key opens everything. Nobody carries a ring of fifteen keys, and nobody gets into a space they have no reason to enter.
It is a commercial tool first. Offices, small business suites, multi-tenant buildings, apartment complexes, warehouses, and any place where more than one person needs different levels of access are the usual candidates. A single-family home almost never needs one, and we will tell you so if that is what you call about.
In Van Nuys the demand tends to come from two kinds of properties: apartment buildings with many doors and frequent turnover, and commercial or office spaces where staff, contractors, and cleaning crews all need some access but not all access. If either describes you, a key hierarchy is worth a conversation.
What problem does a master key system solve?
Most people call us after the key situation has already gotten away from them. The pattern is familiar. Over the years a building collects keys: some copied at a hardware counter, some handed to a former employee, some left with a contractor who is long gone. Nobody can say with confidence how many keys exist for the back office or the mechanical room. Locks were replaced one at a time, so the building now has several unrelated key types, and the manager's keychain is the size of a fist.
That is a key control problem, and it is also a security problem. If you cannot say who holds a key that opens a door, you cannot say who has access to what is behind it. A proper master key system fixes this by putting structure on top of the hardware: a written hierarchy, a record of which key opens which door, and, where the situation calls for it, keys that cannot be copied at just any shop.
How does a master key system work?
Inside a standard pin tumbler lock, the key lifts a set of pin stacks to a precise height so the line between the stacks lines up with the edge of the cylinder. That line is the shear line, and when it is clear the cylinder turns. In a master keyed cylinder, we add extra thin pieces to the pin stacks so that two different cuts will create a clear shear line: the individual key's cut and the master key's cut. The lock accepts either.
Stack that idea across a whole building and you get a hierarchy. We usually explain the levels like this:
- Change key (or day key): opens one lock or one small group, such as a single apartment or a single office.
- Sub-master: opens a defined group of locks, such as every unit on one floor, or every door in one department.
- Master key: opens all the locks in the system, or all the locks in a large section of it.
- Grand master and above: used when a property has several master groups, such as separate buildings on one site, and the owner needs a key over all of them.
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Call (213) 577-1366How we plan and install your master key system, step by step
The planning matters more than the cutting. A system designed on the back of an envelope tends to cause trouble in year three, when you need to add a door or a tenant and find that the structure cannot grow. This is how we approach it.
- We talk through the property: how many doors, which ones need which level of access, who holds keys now, and how often people come and go. For a larger site we like to walk it in person, and our storefront and mobile vans give us a way to do either.
- We inspect the existing hardware. Locks that bind, doors that sag, and worn cylinders all behave differently once they are master keyed, so we note what can be reused and what should be replaced.
- We draw up the hierarchy on paper before anything is cut: which keys exist, what each one opens, and how much room is left for growth. You review and approve it.
- We decide on the key security level: standard keyways, a restricted keyway with controlled key blanks, or duplicate-protected keys, depending on how tightly you need to control copies.
- We pin or rekey the cylinders to the plan. In many buildings the existing hardware can be converted, so the doors do not all have to be replaced.
- We cut and label the keys, test every key on every lock it should open, and also test that the keys that should not open a given lock do not.
- We hand over the key schedule: a record of the system. Keep it somewhere safe, because it is what lets you add doors and keys later without starting over.
Restricted keyways and duplicate-protected keys: what you get and what you do not
A master key system controls who can open what. A restricted key system controls who can make more keys. They solve different problems, and many properties benefit from combining them.
With a restricted keyway, the shape of the key slot is not the common one that any shop stocks. The blanks are controlled by the manufacturer and sold only through authorized channels. Duplicate-protected keys go a step further: copies are made only when the person asking can show authorization, which is usually established when the system is set up. Ordinary key duplication at a hardware store counter will not work on them.
That is the point, and it is also the cost of the system. A copy takes more effort and more lead time than a quick trip to a kiosk. If you run a business with an employee key control system in mind, that friction is the feature. If you think you will want to hand out copies casually, restricted keys will feel like an obstacle, and we will say so before you commit.
One honest note: restricted keyways deter casual copying. They do not make a lock unpickable or a door unbreakable. If your concern is forced entry or bypass, we will talk about the lock grade and door hardware too, which is where our high-security lock options come in. For ordinary copies on a standard system, see our key duplication service.
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We answer around the clock, every day of the year.
Call (213) 577-1366What affects the cost of a master key system?
We do not quote a number on a web page, because a master key system has too many variables for any figure to be honest. What we can do is tell you what moves the cost, so you know what you are paying for when we give you an estimate after hearing about your property.
The main factors are:
- Number of doors and cylinders. More locks mean more cylinders to pin, test, and label.
- Number of levels in the hierarchy. A simple two-level setup is less work than a system with sub-masters and a grand master.
- Whether your existing hardware can be converted. Converting good cylinders is usually the more economical route; replacing worn or mismatched locks adds hardware cost.
- The key security level. Standard keyways cost less than restricted keyways with controlled blanks and duplicate-protected keys.
- How many keys you need cut. Every key holder at every level adds to the total.
- Door and frame condition. If doors bind or latches do not line up, the lock work has to wait until that is fixed, and that is separate work.
- Room for expansion. Planning extra capacity up front costs a little more now and saves a redesign later.
- Scheduling and site access. A single visit during working hours is simpler than coordinating around tenants or after-hours access.
Can you master key locks I already have?
Often, yes. If your locks are standard pin tumbler cylinders in decent condition, we can usually rekey them into a master system without replacing the whole door set. That is typically the lighter-cost route, and it is the one we start with when we assess a property.
There are cases where we will recommend replacing hardware instead: cylinders that are worn out, locks from mixed manufacturers that cannot be keyed to the same system, or hardware that cannot take the extra pins a multi-level system needs. We will show you which locks are which. When door hardware itself is the weak point, our commercial door hardware work covers closers, panic devices, and the rest, so the key system sits on doors that actually close and latch properly.
For a single door that simply needs new keys, you do not need a system at all. That is ordinary lock rekeying, and we will point you there if it is all you need.
How does a master key system fit apartment buildings and landlords?
An apartment master key system is one of the more practical uses. The manager or owner carries a master that opens every unit, plus common-area keys, while each tenant's key opens only their own door. When a tenant leaves, you rekey that one unit to a new change key instead of replacing the lock, and the old key stops working. The master still works, because the cylinder is rekeyed within the same system.
That is the master key rekey process in a nutshell: the structure stays, the individual key changes. It keeps turnover manageable and means you are not hunting for the right key at every move-out. If you manage rentals, our page for landlord locksmith services covers turnover work and related needs.
One caution we give every landlord: the master key is the most valuable key on the property. Decide who holds one, log it, and keep the number small. A system can be perfectly designed and still undone by a master that gets handed around.
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Call (213) 577-1366Master key systems around Van Nuys: what we see on these blocks
Van Nuys has a lot of multifamily housing. The flats are mostly postwar bungalow and ranch tracts, but along corridors like Sepulveda Boulevard and Kester Avenue you find 1960s to 1980s garden apartments and dingbat-style buildings, and the area has a high renter share. Many older buildings still carry their original knob-and-deadbolt hardware. For a property manager in the Kester Avenue area with garden apartments and regular tenant turnover, a master key system is a sensible fit: one master for the manager, change keys per unit, and a quick rekey of a single unit at each move-out. We have written about this setup for a reason, because it is the version of the job that comes up most naturally here.
On the commercial side, the offices around the Van Nuys Civic Center and the shops along the Van Nuys Boulevard corridor need something different. A small office wants a hierarchy: owner, manager, staff, and a janitorial key that opens only the doors cleaning crews need. A multi-tenant building wants each tenant to hold their own suite key without being able to copy it freely, which is where restricted keyways earn their place. And the Raymer Street industrial district near Van Nuys Airport is the kind of area where one site may have office doors, a warehouse door, and a yard gate that all need different keyholders. If the keys also need to be tied to cards or credentials, we can talk through access control installation as a companion to the mechanical system.
Two local details affect the work. First, interior San Fernando Valley summers run hotter than the Westside, and that heat can swell wood doors and frames so latches bind. A master keyed lock has less forgiveness for a door that does not line up, so we check how doors operate before we key them, and we will note any that need adjustment. Second, corrosion is low this far from the coast, so older cylinders here tend to be worn rather than rusted, which usually helps when we are deciding what can be converted.
We work across Van Nuys ZIP codes 91401, 91405, 91406, and 91411. Our storefront is at 10740 Wilshire Blvd in Westwood, roughly 12 miles away, and our mobile vans handle on-site work. If you are locked out of an apartment while you are still planning a system, that is a separate and more urgent job, and our apartment lockout service covers it.
Locked out or need a locksmith now?
We answer around the clock, every day of the year.
Call (213) 577-1366When a master key system is not the right answer
Master keying is not free of trade-offs, and anyone who tells you otherwise is selling something. Every extra level in the system gives a lock a slightly larger set of keys that can open it, which in theory makes it a little easier to defeat than a lock with a single key. That is a known property of the design, and it is why we keep systems no more complicated than they need to be and why we are careful about how many levels we build in.
A master key system may not be right if you have only a handful of doors and a single keyholder, if you need very high security on specific doors that should not be part of the hierarchy at all, or if a credential-based system would suit your staff better. We can leave critical doors off the master entirely, keyed on their own, when that is the right call.
If you are not sure which path fits, tell us what you have and what worries you. We would rather recommend a simple solution that works than build a complicated system you do not need.
Why call Wilshire Lock & Key for a master key system?
Key systems are a long-term commitment, so who builds yours matters. Here is what we can honestly say.
- We have been in business since 1987, and master keying is core locksmith work we have been doing for decades.
- We are one company, not a dispatch service. The person you call is part of the team that does the work, with no middleman passing the job along.
- We have a storefront at 10740 Wilshire Blvd and mobile vans, so we can plan at the counter or on site.
- David, the owner and lead technician, oversees the work.
- The line is answered 24 hours a day, 7 days a week, year-round, at (213) 577-1366.
- We explain the trade-offs, including when you do not need what you are asking about.
Ask any locksmith for their BSIS license
California requires locksmith companies to hold a license from the Bureau of Security and Investigative Services, known as a BSIS LCO license. Whoever you hire to design a system that controls access to your building, ask for their license number and confirm it with the state before work begins. A key system puts your whole property's security in one person's hands, so that question is reasonable and any legitimate company will answer it.
When you are ready, call (213) 577-1366. Tell us the type of property, the approximate number of doors, and what is going wrong with your keys today. We will take it from there and, where useful, point you to our commercial locksmith services for the work around the system.
Frequently asked questions
What is the difference between a master key system and a restricted key system?
A master key system decides which keys open which doors, using a hierarchy. A restricted key system decides who can get copies made, using controlled keyways and blanks. Many commercial properties use both together: the hierarchy for access, and the restriction to keep keys from being copied freely.
Can one key open several doors without all the locks being the same?
Yes. That is what a master key does. Each door keeps its own individual key, and a higher-level key is also able to open a defined group. The locks are keyed differently from each other, but each is built to accept both its own key and the master above it.
Do I need all new locks for a master key system?
Not always. If your existing cylinders are standard and in good shape, we can often rekey them into the system, which is usually the more economical route. Worn, mismatched, or unsuitable locks may need replacing, and we will tell you which ones and why after looking at them.
Is a master key system a good idea for my Van Nuys apartment building?
It often is, particularly where there are many units and regular turnover. You carry a master, each tenant holds a key to their own unit, and you rekey one unit at a time when someone moves out. For a small building with only a few doors, a simpler arrangement may be enough, and we will say so.
Can employees copy the keys from a restricted system?
Not at an ordinary key counter. Restricted keyways use controlled blanks, and duplicate-protected keys require authorization before a copy is made. That deters casual copying, which supports an employee key control system, but it does not replace tracking who holds which key.
What happens if someone loses a master key?
It depends on the level of the key. Losing a single change key means rekeying one lock. Losing the top master is more serious, because it opens every door in the system, and the affected locks may need to be rekeyed. This is why we recommend keeping the number of masters small and logging who holds them.
Can you add more doors to my system later?
Usually, yes, if the system was planned with room for growth. That is why we draw up the hierarchy and keep a key schedule at the start. Systems that were never documented are harder to extend, and sometimes we have to rebuild part of the structure.
How do I know a master key system will not make my building less secure?
Every added level slightly widens the set of keys that can operate a lock, so there is a small trade-off built into the design. We manage it by keeping the hierarchy as simple as the property allows, leaving sensitive doors off the master when appropriate, and choosing the right key security level.
Do you handle master key work outside business hours in Van Nuys?
Our phone is answered 24 hours a day, 7 days a week, at (213) 577-1366. Planning and installation work is usually scheduled around your property, but if something urgent comes up, such as a lost master key on a building you manage, call and we will go from there.
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Reviewed by David, Owner & Lead Technician, Wilshire Lock & Key — in the locksmith trade since 1987.
Last updated 2026-10-11.

