Do Not Duplicate Key Authorization Letter – A Do Not Duplicate Key Authorization Letter (also called a DND key authorization form or restricted key authorization letter) is a formal document that property owners, landlords, business managers, and organizations use to control duplication of keys stamped “Do Not Duplicate,” “Do Not Copy,” or similar warnings. In the United States, this letter helps maintain security for apartments, commercial buildings, HOAs, vehicles, and high-value properties by ensuring only authorized individuals can obtain copies. Whether you manage rental properties in California or a business in New York, understanding and using this letter is essential for preventing unauthorized access.
What Is a Do Not Duplicate Key Authorization Letter?
A Do Not Duplicate Key Authorization Letter is an official written permission on company or property letterhead that instructs a locksmith to duplicate a key marked “Do Not Duplicate” (DND). It includes the requester’s details, property address, number of authorized copies, and contact information for verification.
Locksmiths treat these keys differently because the engraving signals the owner’s intent to restrict copies. While the stamp itself is often just a deterrent, the authorization letter provides proof of permission and protects both the owner and the locksmith from liability.
Why Property Owners and Managers Need a Do Not Duplicate Key Authorization Letter?
Property owners use this letter to:
- Prevent tenants, employees, or contractors from making unauthorized copies.
- Maintain accurate records of who holds keys.
- Comply with state-specific regulations (especially in California).
- Reduce security risks like break-ins from lost or duplicated keys.
Without it, many reputable locksmiths will refuse to cut DND keys, even if legally allowed in most states. This policy upholds the owner’s wishes and avoids creating a false sense of security.
For landlords and facility managers across the USA, the letter is a simple, low-cost tool that strengthens key control systems—far more effective than relying on the stamp alone.
Legal Requirements for Do Not Duplicate Keys in the USA
In the United States, there is no nationwide federal law banning duplication of standard “Do Not Duplicate” keys. The Associated Locksmiths of America (ALOA) states that such keys should be treated like unrestricted keys, noting that the stamp provides a false sense of security and is not effective on its own. Consumers seeking real protection should invest in patented high-security key systems instead.
California is the notable exception. Under Business and Professions Code § 6980.54, it is unlawful for licensed locksmiths to duplicate a key stamped “Do Not Duplicate” (or similar wording) unless it includes the originator’s company name and telephone number and the customer presents a typed Letter of Authorization. The letter must remain on file with the locksmith. Handwritten letters are not accepted.
A few other states (such as North Dakota and Nebraska) have limited restrictions on certain marked keys, but California’s rule is the most comprehensive for everyday DND keys.
For truly restricted or high-security keys (e.g., Medeco, Schlage Primus, ASSA ABLOY, or patented systems), manufacturer authorization plus the letter is almost always required nationwide.
Always check with a local licensed locksmith, as city or county ordinances may add extra rules.
How to Create a Do Not Duplicate Key Authorization Letter?
Creating a valid Do Not Duplicate Key Authorization Letter is straightforward. Follow these steps:
- Use official company or property management letterhead.
- Type the letter (handwritten versions are rejected by most locksmiths, especially in California).
- Include the property address and key description.
- Clearly state who is authorized to request duplicates.
- Provide contact information (phone and email) for verification.
- Specify the number of copies allowed and whether the letter is permanent or one-time.
- Include a signature and date from an authorized representative.
- Require government-issued photo ID from anyone picking up keys.
Keep a copy for your records and update it when personnel change.
Sample Do Not Duplicate Key Authorization Letter Template
Here is a professional, ready-to-use template based on standards used by licensed locksmiths:
[Your Company/Property Management Letterhead]
Do Not Duplicate Key Authorization Letter
Date: [Insert Date]
To Whom It May Concern:
I, [Full Name and Title/Position], am requesting duplication of a key or keys for the property located at [Exact Property Address].
I have the legal authority and rights to make this request (or have been granted authority by the property owner/company).
Owner/Company Name (if different): [Name]
Owner/Company Address (if different): [Address]
The following individuals are also authorized to request keys for this property:
- [Name]
- [Name]
- [Name]
For verification, anyone requesting key duplication must present a government-issued photo ID. Any individual whose name does not appear on this letter or who fails to present ID must be denied service.
This letter shall remain in effect until further written notice. Please contact me with any questions:
Phone: [Number]
Email: [Email Address]
Sincerely,
[Signature]
[Printed Name and Title]
[Date]
Print on letterhead, fill in the blanks on a computer, and bring the original to the locksmith. Many shops provide their own fillable versions.
When and Where to Use a Do Not Duplicate Key Authorization Letter in the USA?
Use the letter for:
- Apartment and rental properties
- Commercial offices and retail spaces
- HOA common areas and pool gates
- Government or institutional facilities
- High-security vehicles or equipment
It is especially important in California but recommended everywhere for liability protection and consistent key control.
Common Mistakes to Avoid with Do Not Duplicate Authorization Letters
- Using handwritten letters (rejected in CA and by most professionals).
- Failing to include contact info for phone verification.
- Not requiring photo ID.
- Relying solely on the DND stamp without a formal letter or patented system.
- Forgetting to update the letter when management or tenants change.
Best Practices for Key Security Beyond the Authorization Letter
For maximum protection:
- Upgrade to patented high-security or restricted key systems.
- Maintain a key log tracking issuance and returns.
- Rekey locks after tenant turnover or employee departure.
- Partner with a licensed locksmith who follows ALOA guidelines.
Frequently Asked Questions About Do Not Duplicate Key Authorization Letters
Can any locksmith copy a DND key with the letter?
Yes—most will once they verify the authorization and ID.
Is the letter required in every state?
No, only California has a specific law, but responsible locksmiths nationwide often require it as best practice.
What if I lost my key and need a copy urgently?
Contact the property owner or manager for a new authorization letter and duplicate.
Do I need a separate form for high-security keys?
Often yes—manufacturer-specific authorization may also be required.
A Do Not Duplicate Key Authorization Letter remains one of the simplest and most effective tools for US property owners and managers to protect their assets in 2026. By using a professional template and working with a licensed locksmith, you ensure compliance, security, and peace of mind.
Need help drafting your letter or finding a trusted locksmith in your area? Contact a local professional today and take control of your key security.