Last updated: February 2026
Here's something most people get backwards: a broken mailbox lock isn't a minor inconvenience, it's an open invitation to identity theft. In Stuart, FL, your mailbox legally belongs to the USPS, which means tampering with a neighbor's is a federal offense, but replacing your own lock is 100% your right and responsibility. Stuart Locksmiths handles mailbox lock replacement throughout Martin County, typically finishing the job in 15-20 minutes for $35-$95 depending on your lock type.
Why Mailbox Security Actually Matters in Stuart
Stuart's mix of waterfront condos, HOA communities along Kanner Highway, and older neighborhoods near SE Monterey Road means mailbox setups vary wildly. Cluster box units (CBUs), wall-mounted boxes, and pedestal units each use different lock cylinders.
Mail theft is a real problem on Florida's Treasure Coast. The FTC reports that identity theft affects over 1.4 million Americans annually, with stolen mail being one of the top 3 physical vectors. A $45 lock replacement is cheap insurance against a $4,000 fraud headache.
If your key broke off inside, the latch stopped catching, or you just moved into a Stuart property and have no idea who has copies of the old key, it's time for a replacement. Our Residential Locksmith team carries the most common cylinder sizes on the truck every day.
Mailbox Lock Replacement: Pricing in Stuart, FL
Pricing depends on the box type and whether you need 1 key or 4. Here's what to expect:
| Mailbox Type | Lock Replacement Cost | Keys Included | Time on Site |
|---|---|---|---|
| Standard Residential Box | $35-$55 | 2 keys | 10-15 min |
| Cluster Box Unit (CBU) | $55-$75 | 2 keys | 15-25 min |
| HOA/Parcel Locker Unit | $65-$95 | 2-4 keys | 20-30 min |
| Broken Key Extraction + Replace | $75-$110 | 2 keys | 20-35 min |
Extra key copies cut on-site run $8-$12 each. No trip back to the shop required.
CBU locks in particular are trickier than they look. The cam mechanism inside has to align perfectly or the lock won't throw. A hardware store cylinder that's "close enough" will fail within 6 months. (Source: Associated Locksmiths of America)
Our Mailbox Lock Replacement Process
Step 1: Assess the Lock and Box Type
Our technician shows up, checks whether you've got a standard residential unit or a CBU, and measures the cylinder diameter. Most Stuart boxes use a 5/8" or 3/4" cam lock cylinder.
Step 2: Remove the Old Cylinder
On a standard box, this takes about 3 minutes with the right cam lock tool. On a CBU where you've lost the key entirely, we pick or drill the cylinder without damaging the box face. We preserve the box itself.
Step 3: Install the New Lock
We install a quality replacement cylinder, not a bargain-bin piece that'll corrode in Stuart's salt air within a year. Coastal hardware sees real wear fast here, so we stock nickel-plated and marine-grade cylinders.
Step 4: Cut and Test Keys On-Site
Keys get cut right there at the truck. We test every key 3 times before we call it done. Smooth operation, correct throw, proper fit.
Step 5: Document and Close Out
We hand you your new keys, confirm the lock is operating correctly, and you're set. The whole process, start to finish, averages 18 minutes for a standard residential box.
Mailbox Lock Types We Replace in Stuart
Not all mailbox locks are the same. Here's a quick breakdown of what we see constantly across Stuart neighborhoods:
- Cam locks (most common in residential boxes) - Standard cylinder with a rotating cam, replaceable in minutes.
- Tubular locks (found in some CBUs and older apartment complexes near downtown Stuart) - Require a tubular key cutter, which we carry.
- Arrow and CompX locks (common in HOA communities near Sailfish Point and Willoughby Golf Club) - Brand-specific cylinders, we stock the most common sizes.
- Master Lock keyed units (budget installs from the 2000s and 2010s) - Replaceable, but worth upgrading to something better while we're there.
If you're dealing with a rusted or salt-corroded lock that won't turn, check out our Lock Rekey Service page - sometimes a rekey is the smarter call if the hardware itself is still sound.
Why Choose Stuart Locksmiths for This Job
We're local. Not a call center in Miami dispatching whoever's available. Stuart Locksmiths operates right here in Martin County, and our technicians know the mailbox setups in communities from Sewall's Point to Palm City and Jensen Beach.
We've completed over 1,400 mailbox lock jobs across the Treasure Coast. That matters because CBU lock replacement has real nuances, and a tech who's done it 12 times is slower and more likely to strip a screw than one who's done it 300 times.
Our trucks are stocked with replacement cylinders for the most common mailbox brands in Stuart. No "we'll have to order the part" delays. Most jobs book same-day, arrive within 2 hours.
We're licensed and insured in Florida. Ask any locksmith you call for their state license number. A legitimate Florida locksmith has a current license through the DBPR. Ours is on file and available on request.
Need more than just a mailbox? We handle full Lock Change & Replacement for doors, gates, and more while we're already at your property.
Mail Theft and Identity Risk: The Numbers
This isn't fear-mongering. These are real figures from credible sources:
| Statistic | Data | Source |
|---|---|---|
| Identity theft reports (2024) | 1.4 million+ | FTC Consumer Sentinel |
| Mail theft complaints to USPIS (2023) | ~299,000 | USPIS Annual Report |
| Avg. fraud loss per victim | $1,100 median | FTC |
| Mailbox lock avg. replacement interval | Every 5-7 years | ALOA Industry Standards |
A working, keyed lock on your mailbox is one of the simplest security upgrades you can make. See our full Home Security Upgrades page for a bigger picture look at protecting your Stuart property.
Frequently Asked Questions
How long does mailbox lock replacement take in Stuart?
Most standard residential mailbox lock replacements take 10-20 minutes on-site. Cluster box units and cases involving a broken key inside the lock may take up to 35 minutes. We do it all in one visit.
Can you replace a mailbox lock if I've completely lost my key?
Yes. We pick or drill the existing cylinder without damaging your mailbox, then install a fresh cylinder and cut new keys on the spot. This is one of the most common calls we get.
Do I need USPS permission to replace my mailbox lock?
For a privately owned residential mailbox, no. You own it, you maintain it. For USPS-owned cluster box units in apartment complexes or HOA communities, the property manager typically coordinates with USPS. Individual mailbox compartments in CBUs are replaced at the owner or HOA level. Call us and we'll walk you through what applies to your situation.
What's the difference between rekeying and replacing a mailbox lock?
Rekeying changes which key operates the existing lock cylinder by adjusting the internal pins. Replacement swaps out the entire cylinder. If your lock is corroded, damaged, or a broken key is stuck inside, replacement is the right call. If the hardware is fine but you just want new keys, rekeying saves a few dollars.
My mailbox lock turns but won't latch. Is that a replacement or a repair?
That's usually a worn cam or a bent latch arm inside the cylinder, not the lock body itself. Sometimes a $15 cam swap fixes it. Sometimes the whole cylinder is shot. We diagnose it on-site before recommending anything.
How much does mailbox lock replacement cost in Stuart, FL?
Standard residential boxes run $35-$55 including 2 keys. Cluster box units cost $55-$75. HOA parcel locker units range $65-$95. If you need a broken key extracted first, expect $75-$110 total. Extra keys are $8-$12 each cut on-site.
Do you carry replacement cylinders for CBUs in Stuart HOA communities?
Yes. We stock the most common CBU lock cylinders including Arrow, CompX, and standard cam lock sizes. The majority of HOA communities in Stuart and Palm City use one of 3-4 cylinder types, and we carry them all.
Will a mailbox lock from Home Depot work as well as what you install?
Honestly, no. The cylinders sold at big box stores are low-security cam locks with 3-4 pin stacks. They're also uncoated steel in most cases, which corrodes fast in Stuart's coastal humidity. We install nickel-plated or marine-grade cylinders that hold up in the salt air near the St. Lucie River and the coast.
Can you replace the lock on a wall-mounted brick mailbox pillar in Stuart?
Yes, those are straightforward. The lock cylinder sits in a standard cam lock housing regardless of the pillar material. Access is from the front panel, and replacement takes the same 15-20 minutes as any other residential job.
I just bought a house in Stuart. Should I replace the mailbox lock?
Always. Previous owners, real estate agents, and contractors all may have had keys. A new cylinder costs $35-$55 and gives you a clean start. We can often do this the same day you call, and pair it with a full Lock Change & Replacement on your doors while we're there.
Do you service mailbox locks in Jensen Beach and Hobe Sound too?
Yes. Stuart Locksmiths covers all of Martin County including Jensen Beach, Hobe Sound, Sewalls Point, and surrounding areas. Same pricing, same response times.
What if my mailbox key broke off inside the lock?
That's a broken key extraction job first, then replacement. We use professional extractors to pull the key fragment without damaging the mailbox. If the cylinder is worn enough to have eaten the key, we replace it at the same visit. See our