Which Keys Cannot Be Duplicated?
Keys that cannot be duplicated at an ordinary hardware store are restricted or patented keys such as Medeco and Mul-T-Lock, high-security laser-cut blades, and car keys with a transponder or smart chip, which must be programmed to the car, not just cut.
A key stamped Do Not Duplicate is a different case: the stamp is a request to whoever cuts it, not a legal block. Apex Locksmith Pros copies car keys at your car from $119+ and rekeys home locks from $35+ per cylinder.
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Why can't patented keys be copied?
A restricted keyway is a key profile the lock maker controls. Medeco, Mul-T-Lock and similar high-security brands supply those blanks only through authorized dealers, and a copy is cut against a registered key holder on file. While the keyway is under patent, making blanks without permission is infringement, so a hardware store simply has no blank to cut. That control is the point of the system: it is how a business knows how many keys to its building exist.
Does "Do Not Duplicate" stop a copy?
Not by law. The stamp is a request from whoever issued the key; many shops honor it as policy and others cut it anyway. If copies have to be controlled for real, the stamp needs to sit on a restricted keyway, or the lock needs to be part of a master key system with a key schedule. On a standard house key, rekeying the cylinder is the reliable way to cut off the copies already out there.
Why does a car key need more than cutting?
Nearly every car built since the early 2000s carries a transponder chip in the key head or a smart fob, and the immobilizer starts the engine only for a key it has registered. A store can cut the blade, and some locations copy certain chips, but a key that has to be added to the car is programmed through the OBD port at the vehicle. Laser-cut, or sidewinder, blades also need a different cutting machine from the one a basic key counter runs.
What can a locksmith copy that a store cannot?
A mobile automotive locksmith carries a code cutter for laser-cut blades and a programmer for transponder keys and fobs, so most car keys a store turns away can be made at the car, including when every key is lost. Restricted high-security house and office keys are the exception for everyone: those go through the authorized dealer for that brand and the key holder on record.
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What Else Do People Ask About This?
Callers in McKinney and nearby cities ask these follow-up questions most often on this topic, and each one is answered in a few plain sentences by our locksmith team.
Can a locksmith copy a key that says Do Not Duplicate?
The stamp is not a law, so it comes down to the shop. Many locksmiths ask for ID or a note from the property owner first. If the key belongs to a landlord or an employer, asking them for the copy is the straightforward route.
Can a Medeco key be copied?
Restricted Medeco keys are cut only through the channel Medeco controls: an authorized dealer working from the registered key holder on file. A hardware store or a key kiosk has no blank for them.
Can a hardware store copy a chip car key?
Some can, depending on the store and the vehicle: certain kiosks and counters clone common transponder chips. Smart fobs, laser-cut blades and keys that must be added to the immobilizer usually need a locksmith or the dealer at the car.
How do I stop people copying my house key?
Rekey the lock so every old copy stops working, then keep track of who gets the new keys. For a business, a master key system on a restricted keyway controls who can order copies at all.
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Related guides: Master key systems for small businesses · Car key types: which one do you have?
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