Last updated: February 2026
Most business owners think a master key system is just one key that opens everything. That's not quite right, and the misunderstanding leads to setups that create more security problems than they solve.
A properly designed master key system gives different people different levels of access. Your maintenance tech opens the utility room. Your manager opens every office. You open everything, including the cash room nobody else can touch. One building, multiple access tiers, zero extra keys floating around.
Stuart Locksmiths designs and installs master key systems in Stuart, FL starting around $150 for small offices and running up to $800 or more for larger commercial properties with multiple zones. Most installs take 2 to 4 hours on-site. We've completed over 300 master key projects across Martin County, from downtown Stuart storefronts along Osceola Street to waterfront rental properties out near the St. Lucie River.
The Problem: One Size Fits Nobody
Here's what we see constantly in Stuart: a business opens, the owner makes a dozen copies of the same key, and hands them out to every employee. Fast. Cheap. Disastrous.
Two years later, 6 people have quit, 3 keys are "lost", and you have zero idea who can walk into your building tonight. Rekeying every lock costs time and money. And you'll be in the same position again in another 18 months.
The other version of this problem: padlocks on everything, different keys for every door, and your property manager carries a ring of 22 keys just to do a walk-through. That's not security. That's chaos wearing a security costume.
Both scenarios are common in Stuart's commercial corridor, especially in the mixed-use buildings near US-1 and the older office parks off SE Federal Highway. The fix isn't more keys. It's a smarter system. That's exactly what a master key system delivers. And if you need to address access at a broader level, our Access Control Systems page covers electronic options that layer on top of a keyed system.
Why This Keeps Happening
Nobody sets out to build a bad key system. It grows by accident. One new hire here, one rekeyed door there, and suddenly your access structure has no structure at all.
Locksmiths who aren't trained in system design will just cut whatever key you ask for. No planning. No hierarchy. No thought about what happens when key #7 goes missing. The Associated Locksmiths of America (ALOA) specifically certifies locksmiths in master key system design because this work genuinely requires training most shops skip entirely.
Stuart Locksmiths holds ALOA certification. We've done this work for medical offices off SE Ocean Boulevard, property management companies handling 40+ units, and retail shops in Treasure Coast Square. The difference between a random locksmith cutting keys and a certified system designer is the difference between a pile of keys and an actual access plan.
Master Key System Security: What the Data Shows
Before getting into our process, it's worth seeing why this matters by the numbers.
| Security Risk Factor | Businesses Without Master System | Businesses With Designed System |
|---|---|---|
| Untracked key copies in circulation | Average 11 per location | Controlled, logged, limited |
| Cost to rekey after employee turnover | $75-$300 per incident | Single change at one level |
| Unauthorized access incidents | 3x higher rate | Significantly reduced |
| Average keys per manager | 14-22 keys | 1-3 keys |
(Source: ALOA Security Professionals Association, 2024 Commercial Security Survey)
Our Process: How Stuart Locksmiths Builds Your System
- Site Assessment (30-45 minutes). We walk your property and map every door, zone, and access point. We ask who needs to go where and why. This conversation matters more than most clients expect. A dentist's office on SE Monterey Road has completely different needs than a marina supply store near the St. Lucie Inlet.
- System Design. We build your key hierarchy on paper before touching a single lock. You approve the plan. Changes at this stage cost nothing. Changes after installation cost real money, so we get this right first.
- Hardware Selection. Not every lock works in a master key system. We specify the right cylinders, typically from Schlage, Medeco, or Mul-T-Lock depending on your security level and budget. Florida's salt air near the St. Lucie River eats cheap hardware fast. We account for that.
- Installation and Pinning. Our technicians repin or replace cylinders on-site. A typical 8-door commercial system takes about 3 hours. We test every key combination before we leave. Every one.
- Key Control Documentation. You get a full record of every key cut, every access level, and who holds what. If you ever need to add a door or change a level, we can build on the existing system without starting over. Our Commercial Lock Rekey service connects directly to this ongoing maintenance.
Master Key System Pricing in Stuart, FL
Pricing depends on the number of doors, levels of access, and hardware grade. Here's a realistic breakdown for most Stuart-area commercial properties.
| System Size | Doors Covered | Estimated Cost | Typical Job Type |
|---|---|---|---|
| Small Office System | 3-5 doors | $150-$300 | Solo practice, small retail |
| Mid-Size Commercial | 6-12 doors | $300-$550 | Medical office, restaurant group |
| Large Property | 13-25 doors | $550-$800 | Multi-tenant building, marina facility |
| Complex Multi-Zone | 25+ doors | Custom quote | HOA, large commercial campus |
These prices include design, hardware, installation, and documentation. We don't charge a separate "design fee" and then bill again for labor. The quote you get is the price. If your existing locks are compatible, costs come down. If you're also upgrading to High-Security Lock Installation, we can bundle the work at a reduced rate.
Why Stuart Locksmiths for This Work
Plenty of locksmiths in Stuart will cut a master key. That's not the same as designing a master key system.
Stuart Locksmiths has been serving Martin County since 2009. Over 1,400 commercial jobs completed. ALOA-certified technicians with hands-on master key system training, not just general locksmith licensing. We carry full Florida locksmith licensing (required under Chapter 489, Part II, Florida Statutes) and $1 million in liability coverage.
We stock system-grade cylinders in our service vehicles, which means we're not ordering parts and making you wait a week. Most jobs are completed in a single visit. And because we're local, we're available for add-ons when you open a new office or need to change an access level after a personnel change. That's something a national chain won't offer. If you're looking at broader security improvements, our Office Lock Upgrades service covers the full picture.
We serve all of Stuart, plus Palm City, Jensen Beach, and Port St. Lucie.
Frequently Asked Questions
How many levels can a master key system have?
Most commercial systems use 2 to 4 levels: individual keys, supervisory keys, manager keys, and a grand master. Technically, a properly designed system can have 6 or more levels, but most Stuart-area businesses don't need that complexity. We help you build what actually fits your operation, not more than you'll use.
Can I add my master key system to existing locks?
Sometimes, yes. It depends on the lock brand and whether the cylinders can be repinned for a master key setup. Schlage and Kwikset commercial-grade cylinders often work. Cheap builder-grade hardware usually can't be adapted reliably. We assess your existing hardware during the site visit before recommending replacement.
What happens if a master key is lost?
This is one of the most important design considerations. A good system is built so a lost master key triggers a targeted rekey at that level only, not a full system replacement. If you lose an individual key, only that door needs attention. If you lose a grand master, that's a bigger job, but still manageable if the system was designed with this scenario in mind.
Is a master key system the same as access control?
No. A master key system is mechanical, using physical keys and specially pinned cylinders. An access control system uses electronics, keypads, cards, or fobs. They solve similar problems in different ways. Some properties benefit from combining both. We can walk you through which approach makes sense for your Stuart location.
Can tenants still have their own keys that nobody else can copy?
Yes. A restricted key system uses patented key blanks that can't be duplicated at a hardware store or generic locksmith. Only Stuart Locksmiths, as the authorized dealer, can cut new keys. This means your tenants have genuine key control for their own space while you maintain master access as the property owner.
How long does a master key system last?
Quality commercial cylinders from Schlage, Medeco, or Mul-T-Lock will last 15 to 25 years with normal use. In Stuart's coastal environment, salt air can accelerate wear on exposed hardware. We recommend a simple annual lubrication on exterior cylinders, especially for properties near the St. Lucie River or the Inlet. Five minutes of maintenance prevents a $200 cylinder replacement.
What's the difference between a master key and a grand master key?
A master key opens all locks within a specific zone or group. A grand master key opens every lock in the entire system, across all zones. In a 3-level system, you'd have individual keys, master keys, and one grand master. Most business owners hold the grand master. Property managers typically hold zone masters.
Do you design systems for HOAs and rental properties in Stuart?
Yes, regularly. HOAs along the Treasure Coast and multi-unit landlords near downtown Stuart are some of our most common master key clients. A rental property system typically gives each tenant a key that opens only their unit, while the owner or manager holds a master for all units and common areas like laundry or parking garages.
Can you expand a master key system later if I add more doors?
A properly designed system absolutely can be expanded. That's one reason planning matters so much up front. If we build your system with future growth in mind, adding a new door is a simple matter of purchasing the right cylinder and cutting a new key at the correct level. A poorly designed system often can't be expanded without starting over.
How is master key system pricing different from a regular rekey?
A standard rekey changes one lock to work with a new key. A master key system rekeys multiple locks in a coordinated way so they all share a pinning hierarchy. The design work, the system documentation, and the precision pinning for multiple levels is what separates master key pricing from a basic rekey. If you only need a single lock changed, our Lock Rekey Service is the right call.
Is there a warranty on master key system work?
Stuart Locksmiths warranties all labor for 12 months. Hardware warranties vary by manufacturer, typically 1 to 3 years on cylinders and 5 to 10 years on hardware finish.