Do Not Duplicate Keys (DND) – Copying & Protecting DND Keys

Do Not Duplicate (DND) Stamped Keys Offer ZERO Protection

Do Not Duplicate Keys Do Not Protect You from Key Copying

How do you stop employees from making copies of your company keys? Restricted keys and high security keys are the best way. Nowadays, anyone can copy a DND key.

Can you duplicate a key that says do not duplicate? Absolutely. Besides being labeled as DND, there is NOTHING that prevents a DND key from being copied. So, yes, you can duplicated a key that says “do not duplicate.”

Getting copies made could be as simple as taking the key to an automated key machine that completely ignores the DND stamp. Or take it to the kid down at the local hardware store that has no idea what “DND” means. Check out our video showing just how easy it is for anyone to make a copy of your Do Not Duplicate key.

If you don’t want your employees making copies of your DND key, you need to upgrade your locks to a restricted, high security key system.

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Quick Q & A

Keys are stamped DND or Do Not Duplicate when that the owner of the key does not want someone to make a copy of it. Any type key can carry this stamp - from the most common house keys to high security keys.
No. When the stamp is a common key, house key or business key, the current automated machines will ignore the stamp completely and anyone can copy the key.
Locksmiths will copy the keys but only with proper authorization. But big box stores and automated machines found at major retail stores will copy it without any authorization.
Convert your locks to a key type that is restricted. This means that the key is not a common key found and is sold only to security professions. The automated machines and big-box stores don’t have access to these keys, so they can’t be copied without authorization.

What is Key Control?

Key control means that you have access and knowledge of every key you own. You know exactly who has a key to every door in your company. Only people you have approved will have a copy of the key, and only people you have designated can make copies of a key. No unauthorized key duplicates can be made. When you get your key back from an employee, you are certain that no copies were made.

What is Bad Key Control?

Bad key control means that anyone who obtained a copy of the key can get a copy made without your knowledge. Once they leave the company, you have no way of knowing if they made a key to your business and you have to go to considerable expense to protect your business (such as having it rekeyed so the old keys no longer work).

Keys Stamped – Do Not Duplicate (DND)

Key Copy Machines Ignore the DND Stamp.

This is the least expensive option to prevent unauthorized key duplication that consists of a standard key being labeled as DND (do not duplicate). The DND stamp was put there to tell locksmiths that these are do no copy keys, and not to copy the key without authorization. Most legitimate locksmiths, and key supply companies, will not copy a DND key unless you can prove you have the authority to make a copy. That is, you need to prove that you own the lock that you are getting a key copy made for. But that is the only protection you get – the honor system.

Besides being labeled as do not copy, nothing actually prevents a DND key from actually being copied. Getting copies made could be as simple as taking the key to an automated key machine that completely ignores the DND stamp. In recent years these machines have popped up at Lowes, Walmart, etc… and they can duplicate a standard business key (Pro Tip: your locksmith copies keys for less than these machines so save some money, take your keys to a locksmith, and support your local locksmith).

Or your employee can take your key to an inexperienced person at a home club that simply doesn’t honor the stamp and have copies.

Restricted Keyways – Solve the Key Copying Problem

This is a more expensive, but much more controlled way to prevent keys from being copied. Restricted keyways are keys that only registered companies have access to. That is, you get a lock and a key that only a security or locksmith company can sell and duplicate. The most restricted keyways may be restricted even further to just one local locksmith in a given territory. So only one company in your city can duplicate the key. When you deploy a restricted key system, should an employee leave and give you back the key you can be confident that they did NOT make a copy of that key. Because of this, you will not have the costly expense of rekeying your business.

Mul-T-Lock High Security Key Duplication Card

If you buy a restricted keyway at ACME locksmith or from your local locksmith near you, you will only be able to get copies of that key at ACME Locksmith. No one issued a key can get copies made anywhere else. All attempts to get copies made by an employee without your authorization will fail because it simply cannot be done. Companies registered with restricted keyways must honor the DND intent and only make keys for someone that has been authorized to do so. In almost all cases, when you are issued a restricted keyway for you business, it comes with a card that must be presented in order to get duplicates made. Without that card, no duplicate.

In addition to the resricted copying benefit, locks with restricted keyways are often high-security. This makes them nearly impossible to pick or to bump and can provide you business a big security improvement. More details on high-security keyways.


Key copy protection is an important part of managing your key control and protecting your assets. ACME Locksmith or your local locksmith will offer both restricted keys and high security keys for copy protection. We honor the DND key stamp regardless of the type of copy protection you have chosen, but automated machines and those big box stores don’t. We will not duplicate a key unless you are on file with us as being the owner of the lock that the key opens or you can prove to us that you are the owner.

Video Transcript:

This is a “Do not duplicate key.” [shows key stamped with Do not duplicate”] Now do not duplicate keys have been used for years by business owners and communities in order to protect your keys from being duplicated. The idea was really simple. Take your key to a professional, they see a “Do not duplicate” (or “DND”) stamp and they know not to make a copy of the key unless the person is authorized.

Well, with the advent of the big box store, a lot of that protection was removed. Uneducated, inexperienced staff will make copies for just about anyone. However, there was still a level of protection as people who were familiar with DND keys wouldn’t copy the key. However, that has all changed.

Do not duplicate keys now offer you ZERO protection against duplication. Automated machinery can now duplicate keys for the most common keys available. Here I’m at a big box store using one of these automated machines. You can see I’m sliding a do not duplicate key into the machine. They machine accepts the key and makes a copy, never looking at the do not duplicate stamp.

Now your employees, or members of your HOA community, can take your do not duplicate keys into any big box store and make as many copies as they want.

So what’s the solution? Restricted keyways. Restricted keyways are just that. Keys that can only be duplicated by some on that has access to that keyway. Most likely a lock or security professional. To implement a restricted keyway system so unauthorized copies still can’t be duplicated, you just replace the cylinders in some of your existing hardware so they use a different keyway. These keyways aren’t available at the key cutting machines or home clubs so it can’t be copied. When you take that key to a security professional any they see that stamp, they’re not going to duplicate it either unless that person has authorization. That way when you get your key back you know no unauthorized copies have been made and you don’t need to have your business rekeyed to protect yourself because you stay protected.