Can You Sue for Trademark Infringement Without Registration?

You can sue for trademark infringement without a federal registration. Section 43(a) of the Lanham Act creates a federal cause of action for owners of unregistered marks, and it opens the door to injunctions, the infringer’s profits, your actual damages, and attorney fees in exceptional cases.¹ The catch is that proving the case is harder and more expensive than it would be with a registration certificate in hand, and the rights you’re enforcing only reach the areas where you’ve actually done business.

What You Own Without a Registration

Common law trademark rights arise automatically the moment you use a distinctive name, logo, or slogan in commerce to identify your goods or services. No government filing creates them. “Use in commerce” means genuine public-facing activity such as selling products under the name, advertising services, or operating a website. Reserving a domain or filing paperwork with the state doesn’t count.

The first business to use a mark in a given market is the senior user and has priority over anyone who adopts the same or a confusingly similar mark later. That priority depends on continuous, good-faith use. Sporadic or token use meant to warehouse a name won’t hold up. When a dispute arises, your proof of ownership comes down to tangible evidence: dated invoices, advertising materials, customer records, and anything else showing when and where you actually used the mark.

Whether Your Mark Is Protectable

Not every business name qualifies for trademark protection. Courts rank marks along a spectrum of distinctiveness, and where yours falls decides whether you have enforceable rights at all.

Fanciful and arbitrary marks, like “Xerox” for copiers or “Apple” for computers, are the strongest and receive protection the moment you use them.
Suggestive marks, like “Netflix” for streaming, hint at a quality of the product without directly describing it and also receive automatic protection.
Descriptive marks, like “Best Buy” for a retail store, describe the product or service and earn protection only after developing “secondary meaning,” which means consumers have come to associate the term with your specific business.
Generic terms, like “computer” for a laptop, can never function as trademarks.

The secondary meaning requirement is where a lot of small-business plaintiffs stumble. If your brand name describes what you sell, you’ll need to show that customers actually think of your company when they hear it. Courts look at how long you’ve used the mark, your advertising spend, customer surveys, sales volume, and whether competitors have copied the name. For highly descriptive names, proving secondary meaning can be the most expensive part of the case.

Where Your Rights Reach

This is where common law rights diverge sharply from federal registration. Your unregistered mark is protected only in the geographic area where you’ve actually used it and built a reputation.

A bakery operating under a particular name in Dallas has enforceable rights in the Dallas metro area. If someone opens a bakery with the identical name in Portland, where the Dallas bakery has no presence, there may be no infringement at all because the markets don’t overlap. Each business can be the rightful senior user in its own territory. Under a doctrine courts have applied for over a century, a junior user who adopts a mark in good faith without knowledge of the senior user can keep operating in its own remote area.

Federal registration would change that. A registered mark gives constructive notice of the claim nationwide, which knocks out the good-faith defense for anyone who starts using a similar mark after the registration date.²

Getting Into Federal Court

A common misconception is that unregistered mark owners need diversity of citizenship and more than $75,000 at stake to reach federal court. That isn’t right. Section 43(a) is itself a federal statute, so any lawsuit under it qualifies for federal question jurisdiction. The district courts have original jurisdiction over civil actions arising under federal trademark law.³ The parties don’t need to be from different states, and there’s no minimum amount in controversy.

The specific federal claim for unregistered marks lives at 15 U.S.C. § 1125(a). It makes anyone liable who uses in commerce a word, name, symbol, or device that is likely to cause confusion about the origin or sponsorship of goods or services.¹ Federal jurisdiction over trademark claims is not exclusive; state courts can hear Lanham Act claims as well, and you can pair the federal claim with state-law trademark and unfair competition claims.³

What You Have to Prove

Registered or not, the central question in any infringement case is whether an ordinary consumer would likely be confused about who’s behind the product or service. Courts apply a multi-factor test, with the exact factors varying by circuit, that typically examines:

Similarity of the marks in look, sound, and overall commercial impression.
Similarity of the goods or services and whether the parties compete or operate in related markets.
Strength of the senior mark, since a highly distinctive or well-known mark gets broader protection.
Marketing channels and whether the parties sell or advertise in the same places.
Consumer care, since buyers spending thousands on a purchase are less likely to be confused than impulse shoppers.
The defendant’s intent, with evidence of deliberate copying weighing heavily toward confusion.
Actual confusion, shown through customer testimony, misdirected emails, or wrong-number phone calls; persuasive when it exists, but not required.

No single factor decides the case. A plaintiff with strong evidence on three or four factors can win even when the rest are neutral. But without a registration, you carry the full burden on every element. There’s no certificate creating presumptions of ownership or validity in your favor.⁴

What You Can Recover

The Lanham Act does not reserve its remedies for registered mark holders. Section 35 of the Act (15 U.S.C. § 1117) expressly applies to violations under § 1125(a), the unregistered mark provision. Win an infringement claim on an unregistered mark and you can recover:

Injunctive relief ordering the infringer to stop using the mark. This is the most common and often the most valuable remedy because it halts ongoing damage to your brand.
The defendant’s profits. You only need to prove the defendant’s gross sales; the defendant then bears the burden of proving any deductions for costs. After the Supreme Court’s decision in Romag Fasteners v. Fossil, willfulness is not a prerequisite for a profits award under § 1125(a).
Your actual damages, including lost profits and other harm directly caused by the infringement.
Enhanced damages, which a court can award up to three times the actual amount depending on the circumstances.
Attorney fees in “exceptional cases,” typically involving willful infringement or litigation misconduct.

All of these are subject to equitable principles, so the court has discretion to adjust awards up or down based on fairness.⁵ The one category genuinely limited to registered marks is statutory damages for counterfeit goods under § 1117(c). For standard infringement, the remedies available to unregistered mark holders are broader than most people realize.

Defenses You Should Expect

Descriptive and Nominative Fair Use

Descriptive fair use applies when someone uses a trademarked word in its ordinary descriptive sense rather than as a brand identifier. A cereal maker named “Honey Crunch” can’t stop a competitor from describing its product as having a “honey crunch flavor,” so long as the competitor isn’t using the phrase as a brand and acts in good faith.¹

Nominative fair use covers references to a brand by name for comparison, criticism, or identification. A repair shop advertising service for “BMW vehicles” is using the BMW mark, but only to identify the product being discussed. Courts require that the user employ only as much of the mark as necessary and do nothing to imply sponsorship.

Laches

If you knew about the infringement and waited an unreasonably long time before suing, the defendant can argue laches, meaning your delay caused prejudice. A successful laches defense can bar monetary recovery entirely, though courts will sometimes still issue an injunction if consumer confusion is ongoing. Laches is less likely to succeed when the infringement was intentional.

Functionality

A product feature that is essential to the product’s use or that affects its cost or quality can’t be claimed as a trademark. If you’re asserting trade dress rights, meaning protection for a product’s overall look, the defendant can argue the feature is functional rather than a source identifier. For unregistered trade dress, you bear the burden of proving the design isn’t functional.¹

How Common Law Rights Can Disappear

Common law rights aren’t permanent. They depend on continued use and can evaporate in ways that catch owners off guard.

Abandonment Through Non-Use

If you stop using the mark with no intention to resume, it’s considered abandoned and anyone can adopt it. Under federal law, three consecutive years of non-use creates a legal presumption of abandonment. Once that presumption applies, the burden shifts to you to prove either continued use or concrete plans to resume, not just a hope of restarting someday. Courts look at objective evidence, not the owner’s say-so.⁶

Genericization

A mark can also be lost if the owner lets it become the generic term for the product. “Aspirin,” “escalator,” and “thermos” were all once enforceable trademarks that lost protection because consumers began using them as common nouns. Police how others use your mark, and make sure your own marketing treats it as a brand name rather than a product category.

Statute of Limitations

The Lanham Act sets no deadline of its own for filing an infringement suit. Courts borrow the most analogous state statute of limitations, which typically runs between three and six years depending on the state. Waiting too long doesn’t just invite a laches defense; it can bar the claim entirely.

The Registration Tradeoff

Suing without registration is viable, but it’s harder on every front. A registration shifts the burden of proof in your favor by creating a legal presumption that you own the mark and have the exclusive right to use it nationwide, and it eliminates the geographic ceiling on common law rights from the registration date forward.² If you’re weighing a lawsuit now, that tradeoff is worth knowing about; if the infringement is already underway, the Lanham Act still gives you a claim.

1
Office of the Law Revision Counsel. 15 USC 1125 – False Designations of Origin, False Descriptions, and Dilution Forbidden
2
United States Patent and Trademark Office. Why Register Your Trademark?
3
Office of the Law Revision Counsel. 28 USC 1338 – Patents, Plant Variety Protection, Copyrights, Mask Works, Designs, Trademarks, and Unfair Competition
4
Cornell Law Institute. Lapp Test
5
Office of the Law Revision Counsel. 15 USC 1117 – Recovery for Violation of Rights
6
Office of the Law Revision Counsel. 15 USC 1127 – Construction and Definitions; Intent of Chapter