Patent Marking Requirements and Benefits

Under the United States Patent Law, 35 U.S.C. § 287(a), damages arising from the infringement of patent claims covering a product do not begin to accrue until an infringer has notice that it is infringing. This can be distinguished from the liability arising from the infringement of claims that cover a method, which begins when infringement begins without any marking requirement. The Federal Circuit Court of Appeals has, however, held that “[w]here the patent has both a product claim and a method claim, if it is possible to mark the product itself with the patent number, then you must do so to give constructive notice to the public.”

The burden of providing notice falls on the patent owner. Marking the patent number on the product, or when that is not feasible on its packaging or label, provides constructive notice to the public of the patent. This results in an infringer being liable for damages from the date infringement began, even if it didn’t have actual knowledge of the patent. The words “Patent” or “Pat.” followed by the patent number must be included on the product, or its packaging or label.

Marking a product or its packaging is sometimes referred to as “traditional patent marking”. In 2011 President Obama signed the Leahy-Smith America Invents Act into law. It provides that “virtual patent marking”, i.e., including on a product or its packaging the URL of a website that associates the patented article with the patent number, also provides constructive notice to infringers. Virtual patent marking requires that the words “Patent” or “Pat.” followed by the URL for a webpage that identifies the applicable patents, e.g.,, be included on the product, or its packaging or label. That webpage must be accessible without requiring payment of a fee, and cannot be behind a “click-through agreement”. Virtual patent marking has the advantage of maintaining the current status of patent(s) easier.

If a patent owner fails to mark a product using either traditional or virtual methods, only damages accruing after an infringer is put on actual notice of its infringement by, for example, receiving a cease and desist letter or being sued, can be recovered. This oversight can result in the in loss of the ability to recover significant monetary damages from an infringer of a product claim.

Comments are closed.