Patent marking is an important but frequently misunderstood aspect of patent law. Properly marking your patented products with the applicable patent numbers can significantly affect your ability to recover damages in an infringement lawsuit. Conversely, improperly marking products as patented when they are not — known as false marking — can expose you to legal liability. At PerspireIP, we help clients develop effective patent marking strategies and compliance programs. This guide explains patent marking requirements, best practices, and the risks of false marking.
Why Patent Marking Matters
Under 35 U.S.C. 287(a), a patent owner may recover damages for infringement only for the period after the infringer had actual notice of the patent. If the patent owner marks their products with the patent number, this constitutes constructive notice to the public — which means damages can be recovered from the date the infringer began infringing, regardless of when they actually learned of the patent. Without marking, the patent owner can only recover damages from the date they gave actual notice to the infringer (typically when a lawsuit is filed or a cease-and-desist letter is sent). This difference can amount to years of lost damages.
Patent marking requirements are particularly important for companies that may not discover infringement until long after it begins. By marking products, you preserve your right to full retroactive damages without having to prove that the infringer had actual knowledge of the patent.
How to Mark Patented Products
The traditional form of patent marking is physical marking — affixing the word patent or the abbreviation pat. followed by the patent number directly on the product or its packaging. The marking must be legible and applied in a location where it would normally be seen. For products that are too small to mark, or where marking is impractical, the marking can be placed on the product’s packaging, label, or accompanying materials.
Virtual Patent Marking
The America Invents Act introduced virtual patent marking as an alternative to physical marking. Under virtual marking, a patent owner can mark their product with the word patent or pat. followed by a URL that links to a webpage listing the patent numbers associated with the product. The webpage must be accessible to the public and must be kept current — as patents are issued or expire, the webpage must be updated accordingly. Virtual marking is increasingly popular because it is easy to update as the patent portfolio changes, unlike physical marking which may require changing molds or labels every time a new patent issues.
Common Patent Marking Compliance Challenges
Maintaining effective patent marking across a product line is more challenging than it appears. Several common issues trip up even sophisticated companies.
- New patents issuing after product launch: when new patents issue that cover an existing product, the product marking must be updated promptly. Failure to update means you cannot recover damages for that new patent before the update.
- Products going out of production: marking requirements apply to products currently being sold, not discontinued products.
- Licensees failing to mark: if your licensees manufacture and sell products under your patent, they must also comply with patent marking requirements. Including a marking obligation in your license agreements is essential.
- Multiple products covered by different patents: for product lines with multiple patented features, carefully mapping which patents cover which products is necessary to ensure correct and complete marking.
The Consequences of Failure to Mark
Failing to comply with patent marking requirements does not invalidate your patent or prevent you from filing an infringement lawsuit. However, it severely limits your damages recovery. Without proper marking or actual notice to the infringer, you can only recover damages for infringement occurring after you filed suit or sent a formal notice letter. In cases where infringement has been ongoing for years before discovery, this limitation can cost you millions of dollars in damages you would otherwise have been entitled to recover.
What Is False Marking?
False marking occurs when a person or company marks an unpatented article with a patent number, the word patent, or any words importing that the article is patented, with intent to deceive the public. Under 35 U.S.C. 292, false marking was historically a qui tam action that allowed any member of the public to file suit and share in any recovery. While the AIA significantly restricted false marking lawsuits (now requiring that the plaintiff suffer competitive harm), false marking still carries risks.
Common false marking scenarios include continuing to mark products with a patent number after the patent has expired, marking products with patent numbers from patents that do not actually cover the marked product, and marking products as patent pending when no patent application is actually pending.
False Marking and Competitive Harm
Post-AIA, only plaintiffs who can demonstrate that they suffered competitive injury from the false marking can bring a false marking lawsuit. This typically means a competitor who was deterred from making or selling a product because of the false marking. Competitors who discover false marking on a rival’s product can now use it as a basis for both a false marking lawsuit and as a defense to a patent infringement claim (by arguing they were misled about the patent status of the product).
Best Practices for Patent Marking Compliance
Developing a systematic patent marking program protects your rights and minimizes false marking risks.
- Implement a patent-to-product mapping: create and maintain a database that maps each patent in your portfolio to the specific products it covers.
- Use virtual marking: implement a virtual marking webpage that is easy to update as your portfolio changes.
- Include marking requirements in license agreements: require all licensees to comply with patent marking requirements contractually.
- Review marking after each patent issuance or expiration: update your marking program whenever a new patent issues or an existing patent expires.
- Audit periodically: conduct annual audits of your product lines to ensure all products are properly marked with all applicable patent numbers.
How PerspireIP Helps with Patent Marking
PerspireIP provides patent marking analysis and compliance program development as part of our comprehensive IP management services. We help clients create patent-to-product maps, establish virtual marking programs, draft licensing agreement marking provisions, and conduct patent marking audits. Our goal is to ensure that every patented product is properly marked so our clients can recover maximum damages if their patents are infringed.
Conclusion
Patent marking is a simple concept with significant practical consequences. Proper marking preserves your right to full retroactive damages in patent infringement cases, while false marking exposes you to legal liability. Developing and maintaining a systematic patent marking program is an essential part of patent portfolio management. PerspireIP can help you build and maintain that program. Contact us today to discuss your patent marking compliance needs.