The most common affirmative defenses to trademark infringement are descriptive (classic) fair use, nominative fair use, laches and acquiescence, abandonment, genericness, functionality, fraud on the U.S. Patent and Trademark Office (USPTO), and the first sale doctrine. Some of these defenses excuse the way a defendant used a mark; others attack the validity of the plaintiff’s mark itself. Which defense fits depends on how the mark was used, how long the owner waited to act, and whether the registration has weaknesses.
If you have received a cease and desist letter or been sued, identifying these defenses early shapes every decision that follows, from how you respond to whether the case is worth fighting at all.
Start With the Plaintiff’s Burden
An affirmative defense is different from simply denying infringement. To win, a trademark owner must prove it owns a valid, protectable mark and that the defendant’s use is likely to confuse consumers about the source, sponsorship, or affiliation of goods or services. A defendant can contest those elements directly. An affirmative defense goes further: it raises additional facts or legal principles that defeat or limit liability even if the plaintiff can make out its basic case.
Even registrations that have become “incontestable” are not immune. Under 15 U.S.C. § 1115(b), an incontestable registration is conclusive evidence of validity and ownership, but it remains subject to a list of enumerated defenses, including fraud, abandonment, descriptive fair use, functionality, and equitable principles such as laches, estoppel, and acquiescence. Our article on trademark incontestability explains how that status is earned and where it stops.
Descriptive (Classic) Fair Use
Trademark law does not let a company take ordinary descriptive words out of the language. The Lanham Act protects a use “otherwise than as a mark” of a term “which is descriptive of and used fairly and in good faith only to describe” the defendant’s own goods or services, or their geographic origin. 15 U.S.C. § 1115(b)(4). The defense also covers a person’s use of their own name in their business. To rely on it, a defendant generally must show that it:
- Used the words in their ordinary descriptive sense, not as its own brand name or logo
- Used them to describe its own goods or services
- Acted fairly and in good faith
In KP Permanent Make-Up, Inc. v. Lasting Impression I, Inc., 543 U.S. 111 (2004), the Supreme Court held that a defendant asserting descriptive fair use does not have to disprove likelihood of confusion; that burden stays with the plaintiff. The Court recognized that “some possibility of consumer confusion must be compatible with fair use,” while noting that the degree of likely confusion may still bear on whether a use is objectively fair.
Nominative Fair Use
Nominative fair use applies when a business uses another company’s mark to refer to that company’s own products, such as an independent repair shop advertising that it services a particular brand, a reseller identifying the products it carries, or comparative advertising. The Ninth Circuit’s influential test in New Kids on the Block v. News America Publishing, Inc., 971 F.2d 302 (9th Cir. 1992), asks whether the product is not readily identifiable without the mark, whether only as much of the mark as reasonably necessary was used, and whether the user did anything to suggest sponsorship or endorsement.
Courts do not treat this doctrine uniformly. The Sixth Circuit, which covers Michigan, declined to adopt the Ninth Circuit’s analysis in PACCAR Inc. v. TeleScan Technologies, L.L.C., 319 F.3d 243 (6th Cir. 2003). Where you are sued can therefore affect how the defense is framed. For a deeper comparison, see classic vs. nominative trademark fair use.
Parody and Expressive Use After Jack Daniel’s
Parody is often described as a trademark defense, but the law narrowed significantly in 2023. In Jack Daniel’s Properties, Inc. v. VIP Products LLC, 599 U.S. 140 (2023), a dog-toy maker sold a “Bad Spaniels” squeaky toy mimicking the Jack Daniel’s whiskey bottle. The Supreme Court held that when an alleged infringer uses a trademark as a designation of source for its own goods, the First Amendment-based Rogers test does not apply, and the ordinary likelihood-of-confusion analysis governs. The Court also held that the dilution statute’s exclusion for noncommercial use does not shield parody or commentary when the mark is used as a source identifier for the defendant’s own products.
Parody is not irrelevant after Jack Daniel’s. A clear parody may make confusion less likely. But a business that puts a humorous take on someone else’s mark on its own products should expect that joke to be tested under the standard confusion factors. More on this in our article on trademark infringement and the First Amendment.
Laches, Acquiescence, and Estoppel
Trademark owners who sit on their rights can lose some or all of their remedies. The Lanham Act lists laches, estoppel, and acquiescence among the defenses available even against incontestable registrations. 15 U.S.C. § 1115(b)(9).
Laches requires a lack of diligence by the trademark owner and resulting prejudice to the defendant. In Nartron Corp. v. STMicroelectronics, Inc., 305 F.3d 397 (6th Cir. 2002), the Sixth Circuit looked to Michigan’s three-year limitations period for injury to personal property, measured from when the owner knew or should have known of the infringing use. Delay beyond that period is presumed unreasonable and prejudicial, although the owner can rebut the presumption. The court also explained that laches bars only damages incurred before the lawsuit was filed; it does not by itself prevent injunctive relief or recovery of post-filing damages. If you face a claim in Northern Michigan, a trademark attorney in Traverse City can help you assess timing defenses such as laches.
Acquiescence is a stronger version of the same idea: it applies where the owner, by words or conduct, effectively consented to the defendant’s use. Estoppel can apply where the defendant reasonably relied on the owner’s representations. These defenses turn heavily on documents, such as old emails, prior correspondence, or a history of coexistence, so preserving that evidence early matters.
Attacking the Validity of the Plaintiff’s Mark
Many strong defenses target the mark itself. Several of these grounds also support a petition to cancel a federal registration “at any time” under 15 U.S.C. § 1064(3).
Abandonment
A mark is abandoned when its use has been discontinued with intent not to resume use, and nonuse for three consecutive years is prima facie evidence of abandonment. A mark can also be abandoned when the owner’s conduct causes it to become generic or otherwise lose its significance as a mark. 15 U.S.C. § 1127. See abandonment of trademark rights for how courts evaluate these claims.
Genericness
No one can own the common name for a product or service. The statute provides that no incontestable right can be acquired in a generic name, 15 U.S.C. § 1065, and in USPTO v. Booking.com B.V., 591 U.S. 549 (2020), the Supreme Court confirmed that whether a term is generic depends on its meaning to consumers. In Nartron, the Sixth Circuit found the term “smart power” generic and therefore unprotectable.
Functionality
Trademark law does not protect functional product features, which are the domain of patent law. Functionality is an enumerated defense under § 1115(b)(8). In TrafFix Devices, Inc. v. Marketing Displays, Inc., 532 U.S. 23 (2001), the Supreme Court held that a dual-spring sign design claimed in expired utility patents could not be protected as trade dress, emphasizing that an expired patent is strong evidence that the claimed features are functional.
Fraud on the USPTO
A registration obtained fraudulently is subject to challenge under § 1115(b)(1) and § 1064(3). The standard is demanding. In In re Bose Corp., 580 F.3d 1240 (Fed. Cir. 2009), the Federal Circuit held that fraud requires a knowingly false, material representation made with intent to deceive the USPTO, proven by clear and convincing evidence. An honest misunderstanding or negligent error is not enough. Related unclean hands arguments focus on inequitable conduct by the plaintiff connected to the rights it is asserting.
Prior Use
A defendant that adopted a mark without knowledge of the registrant’s prior use, and used it continuously before the registrant’s constructive-use date, may keep using it in the area where that continuous prior use is proved. 15 U.S.C. § 1115(b)(5). Section 1115(b)(6) provides a related defense for a mark registered and used before the plaintiff’s registration and not abandoned.
The First Sale Doctrine
Reselling genuine branded goods is generally not infringement. As the Sixth Circuit explained in PACCAR, the first sale doctrine applies when a purchaser does no more than stock, display, and resell a product under its trademark. It does not protect a reseller that uses the mark in a way likely to make the public believe it is part of the producer’s authorized sales network, and it does not protect goods that are altered or not genuine. For e-commerce sellers, how listings and advertising describe the relationship with the brand often decides the issue.
Extraterritoriality: Where the Use Occurred
In Abitron Austria GmbH v. Hetronic International, Inc., 600 U.S. 412 (2023), the Supreme Court held that the Lanham Act’s core infringement provisions, 15 U.S.C. §§ 1114(1)(a) and 1125(a)(1), are not extraterritorial. They reach only domestic use of a mark in commerce. A defendant whose challenged use occurred entirely outside the United States can argue that the claim falls outside the statute.
Why Early Defense Strategy Matters More Today
The Trademark Modernization Act of 2020, signed into law on December 27, 2020, restored a rebuttable presumption of irreparable harm for trademark owners seeking injunctions. A plaintiff that shows a violation, or a likelihood of success on the merits at the preliminary injunction or temporary restraining order stage, now receives that presumption. 15 U.S.C. § 1116(a). Defendants can no longer count on plaintiffs struggling to prove irreparable harm, which makes developing fair use, laches, and validity defenses at the outset more important than ever.
Practical early steps include:
- Preserving records showing when and how you adopted and used the name, logo, or product design
- Gathering evidence of when the trademark owner first knew about your use
- Reviewing the plaintiff’s registration file for gaps in use, questionable specimens, or overly broad claims
- Documenting third-party use of the same or similar terms, which can support weakness or genericness arguments
Get Help Evaluating Your Defenses
A trademark infringement claim is not the end of the conversation. Depending on the facts, a well-supported defense can defeat the claim, limit damages, or give you leverage to negotiate a coexistence agreement or rebrand on your own timeline. If you have received a demand letter, our guide to the trademark infringement cease and desist letter is a good place to start.
If you have been accused of trademark infringement or need to evaluate the strength of a claim against you, the trademark infringement attorneys at Revision Legal can assess your defenses and build a strategy to protect your business. Contact us through the form on this page or call (855) 473-8474.
