The Insufficiency of a “Patent Pending” Mark: The Logic of § 287’s Notice Requirement

By Luke MacDowall *

The validity of marking products as “patent pending” has long been recognized as a legitimate way to put a competitor on notice of potential future infringement of a patent once that patent has issued. See, e.g., Ex parte Bonnie-B. Co., 1923 C.D. 42 , 313 O.G. 453 (Comm’r Pat. 1922). However, even with a “patent pending” marking, an inventor does not secure rights to damages (even if the patent eventually issues and the infringer has knowledge of the patent and its infringement) when the patentee fails to change the marking on its products in compliance with 35 U.S.C. § 287(a). This post briefly explores the logic behind § 287(a) to explain why “patent pending” markings are not enough to entitle patentees to damages.

I.                   The General Legal Duties of a Patentee to Provide Notice

Recovery of damages in a patent infringement action is limited by 35 U.S.C. § 287(a), which imposes a duty upon patentees to inform would-be infringers of the existence of a patent. A patentee must establish either: “(1) that he gave public notice of his patent by affixing the word ‘patent’ or the abbreviation ‘pat.’ together with the patent number on the patented articles, or failing that, (2) that the infringer was notified of the infringement and continued to infringe thereafter, in which event, damages may be recovered only for infringement occurring after such notice.” Lemelson v. Fisher Price Corp., 545 F. Supp. 973 (S.D.N.Y. 1982) (citing, 35 U.S.C. § 287).  The Supreme Court has made clear that the patentee bears the burden of proving notice through marking or actual notice to the defendant infringer. See Dunlap v. Schofield, 152 U.S. 244, 247, 14 S. Ct. 576, 38 L. Ed. 426 (1894). Therefore, § 287 requires “more than mere knowledge by the accused infringer of the violation: it mandates that the patentee take affirmative action to protect its rights by notifying the infringer of the purported violation. *532 (emphasis added) See also Amsted Indus., 24 F.3d at 187. 

II.                The Logic of § 287’s Notice Requirement

As recently explained by one court, the patent right requires a balancing act between the rights of an inventor to profit from her invention and the right of the marketplace to improve upon that design in the future. Thus, inventors are granted a “limited monopoly” over a product design. Arlington Industries, Inc. v. Bridgeport Fittings, Inc., 290 F.Supp.2d 508, 519 (M.D.Pa. 2003) citing Mazer v. Stein, 347 U.S. 201, 219, 74 S.Ct. 460, 98 L.Ed. 630 (1954). However, this right carries with it the duty to make “known and ascertainable to the general public” the innovation in the patent application. Arlington Industries, 290 F. Supp. 2d at 519 citing Markman v. Westview Instruments, Inc., 517 U.S. 370, 373, 116 S.Ct. 1384, 134 L.Ed.2d 577 (1996).

The logic of this balancing act seems obvious:  the marketplace needs to be informed of patented inventions to make intelligent distinctions between those products subject to free development and those already claimed. However, on a second look, the Patent Act really requires more than an informed marketplace. As one court put it, patent rights are really granted in an “exchange for [a patentee’s] disclosure,” and until a patentee fulfills its disclosure duty her rights to seek damages for patent infringement are curtailed. Arlington Industries, 290 F. Supp. 2d at 519 (emphasis added).

1.      Marking and the Insufficiency of “Patent Pending” Marks

Because of this duty interpreted as requiring the patentee to take “affirmative action” rather than rely on the information the market may have ascertained on its own, patentees are precluded from relying on “patent pending” marks to satisfy § 287. Under § 287(a), a patentee is barred from recovering any damages for patent infringement unless the patentee gives “notice to the public” by affixing to its product the word “patent” or “pat.” along with the patent number. “Until such time as the manufactured article is marked ‘patented’ there is no actual notice to the public that the article is protected by the patent laws.” Steinthal v. Arlington Sample Book. Col, 94 F.2d 748, 749 (3rd Cir. 1938) (emphasis added).

Moreover, § 287(a) is not satisfied by the marking with the words “patent pending.” The marking must contain the word “patent” or the abbreviation “pat.” together with the authorized patent number. MacPike v. American Honda Motor Co. Inc., 29 USPQ2d 1526, 1530 (N.D. Fla. 1993). In MacPike, the plaintiff tried to argue that the defendant had “constructive notice” because some of the patented units were marked “patent pending” while others had the actual patent number. The Court held that the failure to mark the products in accordance with the strict requirements of § 287(a) foreclosed the award of damages. MacPike v. American Honda Motor Co., 1993 U.S. Dist. LEXIS 18970, *15-16 (N.D. Fla. Oct. 1, 1993). See also Maescher v. reliance Manufacturing Co., 144 F.Supp. 574, (S.D. Indiana 1956) (finding that “patent pending” followed by the patent number was insufficient), and  State Indus. v. A.O. Smith Corp., 751 F.2d 1226, 1236 (Fed. Cir. 1985) (“A patent pending; notice gives one no knowledge whatsoever. It is not even a guarantee that an application has been filed.  Filing an application is no guarantee any patent will issue and a very substantial percentage of applications never result in patents. What the scope of claims in patents that do issue will be is something totally unforeseeable.”) and Conopco, Inc. v. May Dep’t Stores Co., 46 F.3d 1556, 1562 (Fed. Cir. 1994) (marking products with “patent pending” is insufficient to support a finding of willfulness).

2.      Actual notice

A patentee who has failed to appropriately mark its products, may recover damages if it proves the defendant-infringer had notification of infringement in the form of “actual knowledge.” For purposes of proving notice, the “[f]iling of an action for infringement shall constitute such notice.” 35 U.S.C. § 287(a).

However, actual knowledge of the patent itself is not sufficient. For example, in Devices for Medicine, Inc. v. Boehl, the Federal Circuit held that § 287 requires proof that the defendant-infringer had notice of its actual infringement, finding that actual notice of the patent itself including the patent number was insufficient. 822 F.2d 1062, 3 USPQ2d 1288 (Fed. Cir. 1987). Courts have also specifically rejected tests that are dependent on the state of mind of the reasonable infringer. For example, in International Nickel Co. v. Ford Motor Co., the court rejecting the plaintiff’s argument that “‘. . . damages may be recovered for infringement occurring after the infringer is, or should have been, aware of such infringement.’” 166 F. Supp. 551, 567 (S.D.N.Y. 1958). Instead, it held that the law required the patentee to give the defendant “express” notification that the defendant was “infringing a particular patent.” Id.

Thus, the duty to disclose must be fulfilled irrespective of whether or not an infringer has “actual knowledge” of a patent to entitle the patentee to damages. In Arlington Industries, the patentee argued that the infringer had “actual knowledge” of the patents because it had solicited opinion letters from counsel to determine whether its product was infringing any other patents. The court dismissed this argument as improperly “conflate[ing] ‘knowledge’ and ‘notice’.” 290 F.Supp.2d at 531.  

Therefore, “patent pending” notifications would be insufficient to prove actual notice within the meaning of § 287(a). These types of notifications only serve to inform the public about a potential violation and may even be used in conjunction with other evidence that demonstrates “actual knowledge” of infringement. However, the importance of § 287 lies in its requirement that the patentee take the specific affirmative steps of appropriately marking patented products; failure to do so bars the patentee from recovering damages.

In conclusion, “patent pending” marks may serve to inform the public about possible patent infringement but they do not rise to the level of discharging the statutory duty imposed on patentees to provide notice under § 287; allowing these marks to satisfy the disclosure requirement would simply relax the burden on patentees and thus imbalance the “exchange” that grants patentees the right to patent protection for actively fulfilling their statutory duty.


*Luke MacDowall is a third-year law student at Wake Forest University School of Law.  He holds a Bachelor of Arts in Philosophy and History from Trinity University in San Antonio, Texas.  While at Wake Law, Mr. MacDowall led the National Trial Team as team-captain and participated on the National Moot Court team.  In addition, Mr. MacDowall worked in the intellectual property litigation department at Womble Carlyle Sandridge & Rice, PLLC.  Upon graduation in May 2011, Mr. MacDowall intends to practice general business litigation with special emphasis on employment and labor law.