USPS controls the master Arrow lock, but when a thief with a stolen key cleans out an entire multi-drawer mailbox, aka cluster box unit or CBU, quickly and silently, HOA residents and boards will come to you looking for answers.
Get program information →The USPS Arrow key system was designed for efficiency, not security. A single master key unlocks every mailbox cluster on a carrier’s route, as well as every CBU in that zip code. When one key is stolen, mail for hundreds – even thousands – of people is instantly vulnerable.
Criminals aren’t stumbling onto this by accident. They’re robbing mail carriers at gunpoint specifically for their Arrow key. What used to be street crime is now an organized operation: steal the key, open dozens of CBUs, grab all the mail, find the checks, wash them with household chemicals, then deposit thousands into mule accounts – often within hours of delivery. The thieves are also after social security numbers, account numbers, and gift cards.
“Someone with a master key broke into our CBU. A USPS supervisor informed me that it would be impossible to re-key our mailbox cluster because all CBUs sharing the same zip code have the same master key, and all of them would need to be re-keyed.”
– Seattle resident, after a second CBU break-in within 7 months (2025)“In early December, mail carriers were robbed of their master keys at gunpoint and in the weeks since, mail theft has grown to unprecedented levels. The thieves are brazen – many mailbox break-ins are occurring during broad daylight, minutes after mail is delivered.”
– Denver, MCA notice to over 1,200 CBU residents, 2026Here are some numbers that give you an idea of the scope of the problem:
Mailbox Protector attaches to the CBU directly over the Arrow lock, adding a hardware barrier that thieves can’t get through without investing a lot of time and/or making a lot of noise. Once installed, Mailbox Protector hardens your CBU, making it a difficult, unattractive target – and in a city with hundreds of other unprotected CBUs, aka softer targets, the instantly visible deterrent provided by Mailbox Protector will make thieves move on.
Organized theft rings prioritize speed and volume. A visible security device blocking your CBU’s Arrow lock will make thieves move on to easier targets.
Mailbox Protector is a robust metal barrier that can only be opened using word-based combinations. Due to its purely mechanical construction, there is nothing to charge, connect, or hack. And if a code gets in the wrong hands, Mailbox Protector can be re-programmed in minutes.
The USPS does not have an answer to the mail theft problem – and local postmasters don’t have the tools, technology, or resources to stop it. But they suffer the consequences every day – dealing with customers upset about their stolen mail, addressing carrier safety concerns, and burning resources trying to cope with an issue that is diverting them from their core mission: delivering the mail efficiently. Therefore, they have lots of reasons to want a solution to the widespread, persistent, and resource-draining problem of mail theft.
Mailbox Protector was invented in Silicon Valley where, as of mid-2026, several postmasters have OK’d numerous pilot installations. Specifically, dozens of mailbox clusters in several Bay Area cities are now equipped with Mailbox Protector, and the early results are encouraging. For the first time ever, thieves can’t use their stolen keys to open mailbox clusters and there is the promise of an enduring solution to the raging mail theft problem.
Full disclosure: the USPS does not yet endorse Mailbox Protector, but because CBUs belong to the customer, several Northern California postmasters have allowed it to be installed by HOA managers and apartment managers, and mail carriers are using it because it is the only anti-mail theft product on the market… and it works!
Spoiler alert: the USPS isn’t replacing millions of Arrow locks with a modern, theft-stopping solution anytime soon for two reasons: they don’t have a technology solution and, even if it existed, they don’t have the money to buy and install anti-theft devices on millions of CBUs nationwide.
Therefore, property managers like you must take the first step toward improving mailbox security by telling your boards about Mailbox Protector. The good news is that the concept has been proven, more Mailbox Protectors are being installed every week, and your local postmaster may have already heard about it from one of his or her Silicon Valley colleagues.
Every major investigation reaches the same conclusion: USPS cannot fix this at scale, and the arrow key theft market is growing faster than any government response.
Choose the level that fits where you are right now.
Mailbox Protector is currently deployed at pilot sites. We’re selecting the next cohort of HOA and property management partners now. Ideal for communities with 50+ CBUs experiencing active theft incidents.
Lock in priority pricing and delivery position now. Pre-orders ship in order of confirmation. Quantity pricing available for multi-property portfolios.
Not ready to commit yet? Sign up to receive rollout announcements, pilot program results, and availability updates by email.
Check everything that applies – no commitment required.
Fill out the form below and check all that apply. We’ll follow up based on your selections.
We’ll be in touch within one business day based on your selections. If you applied for the pilot program, expect a short questionnaire about your community’s CBU count and current theft situation.