Key Duplication Laws: What's Legal and What Isn't

Key duplication law is one of those topics where the internet confidently repeats something that is not true: that stamping "Do Not Duplicate" on a key makes copying it illegal. It does not, in any US state. What actually governs who can cut your key is a mix of state locksmith licensing, patent law, and simple ownership verification, and the practical rules are clearer than the myths suggest. Here is how it really works, including what we are required to do before cutting anything in North Carolina.

"Do Not Duplicate" is a request, not a law

Those three words are a policy statement aimed at the person behind the counter, not a legal restriction. A hardware store or kiosk that copies one is not committing a crime. Most major chains decline anyway as internal policy, which is why people assume it is legal force, but the key itself is not protected by anything except that etching.

The practical consequence: if key control genuinely matters to you (a rental, an office, a shared building), "Do Not Duplicate" buys you very little. What actually works is the next section.

What does provide real key control: restricted keyways

A restricted or patented keyway is a physical and legal mechanism together. The blank is a patented profile that ordinary suppliers cannot buy, and it is distributed only to authorized dealers who are contractually bound to verify authorization before cutting. Two things stop an unauthorized copy: the machine has no blank that fits, and the dealer's agreement forbids it.

This is what businesses should ask for when a departing employee is the reason they are calling. It is also why a commercial master key system is designed around a restricted keyway rather than around a stamp.

Patents expire, which matters more than people expect: once a keyway's patent lapses, aftermarket blanks appear and the restriction becomes ordinary. If you were sold "restricted" hardware years ago, it may not be restricted now.

What a licensed locksmith must do before cutting

North Carolina licenses locksmiths through the NC Locksmith Licensing Board, and licensure comes with obligations that go beyond skill: background checks, license display, and the verification duties that make the trade trustworthy. In practice, before we duplicate or originate a key we confirm:

• Vehicles: photo ID plus proof of ownership (title or registration matching the ID), VIN verified against the windshield plate and door jamb. If the car is registered to someone else, that person authorizes the work, not the person standing there.
• Homes: ID plus evidence of the right to be there, which usually means a deed, a lease, or a utility bill in that name at that address.
• Businesses: authorization from the owner or an officer, not simply whoever has the key in hand. A manager holding a key is not automatically the party allowed to duplicate it.
• Restricted keyways: the signature card or authorization list held on file by the system's dealer.

We log this. It is the boring part of the job that separates a licensed locksmith from a van with a slogan, and it is exactly the part a scam operation skips. If someone offers to copy your neighbor's key with no questions asked, that tells you what else they are willing to skip.

Tenants, landlords, and shared property

Two situations produce most of the confusion:

Renting. In most cases a tenant may have a copy of their own unit key for their own use; what they generally may not do is rekey the lock or hand copies out contrary to the lease. Landlords, in turn, cannot simply lock a tenant out or change locks to force a move-out. The lease and state landlord-tenant law govern the details, and we ask to see the lease before doing rekey work at a rental for exactly that reason.

Selling or buying a home. The moment you take possession, you own the hardware and can do as you like with it, which is precisely why the first thing we recommend is rekeying every exterior cylinder. You have no idea how many copies exist: prior owners, contractors, cleaners, a realtor lockbox, a neighbor for the dog. Our move-in rekey case study in Cornelius walks through what that actually involves.

Frequently asked questions

Is it illegal to copy a key stamped "Do Not Duplicate"?

No. It violates no state or federal law. It is a request that reputable shops honor as policy, but it carries no legal weight and provides no real security. Use a restricted keyway if you need actual control.

Can a locksmith refuse to copy my key?

Yes, and a good one will when ownership is unclear, when the key belongs to a restricted system without authorization, or when something about the request does not add up. That refusal protects you on the day someone else asks about your key.

Can I copy my car key myself from an online blank?

Cutting a blank is legal if you own the vehicle. The catch is technical rather than legal: anything newer than the early 2000s carries a transponder chip that must be programmed to the car, and marketplace fobs are frequently locked to a previous vehicle. Our where to get a car key made guide compares every option honestly, including the ones that cost less than we do.

What about apartment building fobs?

We do not copy building or apartment RFID fobs. Those belong to the property's access-control system, and duplication is the property manager's call, not ours or yours.

The practical summary

If you want a key that cannot be copied casually, ask for a restricted keyway, not a stamp. If you just moved in, rekey rather than worry about copies. And if you are calling about a key that is not obviously yours, expect to be asked for paperwork, because the locksmith who asks is the one you want touching your locks. We are licensed in North Carolina under #3024, we verify every job, and we will tell you on the phone what documents to have ready before we roll.