United States: Put the Patent Number on the Product

Article by Kenneth E. Radcliffe and Ronda P. Moore, D.V.M.

Every patent issued by the United States Patent and Trademark Office includes, at the end of the patent, at least one "claim" that defines the scope of the patent owner’s legal right to exclude others. Where a patent includes one or more claims covering a product, in order to maximize the amount of money that an owner of the patent can recover from an infringer of the patent, the owner should put (or "mark") the word "patent", or the abbreviation "pat.", together with the number of the patent on the patented product. When, because of the character of the patented product, the product can not be marked with the patent number, the patent number should be put on a label and the label fixed to the product or its package. Absent such marking, the patent owner is able to collect money damages only for infringement occurring after the owner actually notified the infringer of the infringement.

As a result of marking a patented product with the patent number, the public is given notice that the product is patented, and any infringers are in effect deemed to have been notified of their infringement of the patent. Marking a patented product is, therefore, a powerful tool for patent owners. At the very least, it provides for the possibility of collecting larger monetary rewards from infringers, including infringers that a patent owner has not yet discovered.

In certain instances, the patent marking provision of United States patent law does not apply. For example, if a company does not make or sell a product covered by the claims of a patent that the company owns, and if the company has not authorized any licensee to make or sell the product, patent marking does not apply because there is nothing to mark. Also, when all of the claims of a patent are directed to methods or processes, a patent owner generally need not mark any products with the patent number. But, when a patent claims both a product and a method/process that "relates to" the claimed product (e.g., that uses or produces the claimed product), the patent owner (if it makes or sells the product, or if it has authorized another to do so) must mark the product in order to recover money damages for any infringement occurring before the owner actually notified the infringer of the infringement.

Where patent marking does apply, United States patent law does not dictate when the marking must begin. A company is not required to start marking its patented product immediately upon the issuance of its patent in order to be eligible to recover money damages from an infringer. Rather, the company may begin to mark its patented product at any time during which its patent remains enforceable. A delay in marking the patented product, however, may prove costly, as money damages can only be recovered from an infringer from the time the patent marking began (absent earlier actual notice of infringement by the patent owner to the infringer).

After patent marking has begun, it should be substantially consistent and continuous. The patent marking also should be visible and legible.

Entities that are authorized by the patent owner to make or sell the patented product should observe the patent marking rules, and the patent owner should see that this happens. While courts recognize that patent owners may face difficulties in ensuring that licensees comply with the patent marking rules, patent owners must nevertheless make reasonable efforts to ensure that licensees do in fact comply. Patent owners can include in licenses obligations on the licensees to mark patented products, and patent owners also can undertake other reasonable acts to ensure that licensees are aware of the duty to mark and are complying.

Patent marking should be done not only timely and in accordance with the applicable rules, but also accurately. So-called "false marking" can result in fines in the United States. False marking occurs where, for example, a company with the intent of deceiving the public marks an unpatented product as patented.

Patent owners can periodically review their products and the coverage of their patents, and maintain a patent marking list or matrix. Such a list or matrix indicates which patents correspond to which products and can be used by a patent owner to ensure that its patented products are accurately marked. And this, in turn, can result in larger money damages for the patent owner from infringers of the owner’s patents.