Common Law Trademark: 2025 Guide

A common law trademark provides legal protection for a brand name, logo, or slogan without requiring formal registration. Businesses automatically gain some trademark rights simply by using a unique mark in commerce. However, these rights are limited in scope and can be harder to enforce compared to a federally registered trademark.

Failing to protect a trademark properly can lead to disputes, lost branding rights, or costly rebranding efforts. This guide explains how common law trademarks work, their limitations, and how businesses can strengthen their rights.

What is a common law trademark?

A common law trademark is a trademark that gains legal protection through use in commerce rather than registration. This means that as soon as a business starts using a unique name, logo, or slogan to identify its goods or services, it may have some legal rights to that mark.

Unlike federally registered trademarks, which provide nationwide protection, common law trademarks are typically limited to the geographic area where the mark is actively used. Because these trademarks are not recorded with the United States Patent and Trademark Office (USPTO), enforcing rights against infringers can be more difficult.

Examples of Common Law Trademarks in Action

A clothing brand selling online under an unregistered name may have limited common law protection if it can prove consistent commercial use.

A local bakery in Chicago that has used the name “Sweet Bites” for 10 years may have common law rights to that name in its geographic area.

Common Law Trademark vs. Registered Trademark

How to Establish Common Law Trademark Rights

Step 1: Choose a unique, non-generic brand name, slogan, or logo

A business gains stronger common law trademark rights if the mark is distinctive. Generic or descriptive marks are harder to enforce. Names like “Best Coffee Shop” may not be protectable, while “Java Jolt” would have a better chance of legal recognition.

Step 2: Use the trademark publicly in commerce

Common law rights are based on actual use, not intent. Businesses must publicly use the mark on websites, packaging, advertising, or signage to establish rights.

Step 3: Maintain records of first use and continuous use

Keeping documentation of when the mark was first used, where it was used, and how it was marketed can help establish trademark rights in case of a dispute.

Step 4: Use the ™ symbol to indicate unregistered trademark rights

Businesses using common law trademarks can place the ™ symbol next to their brand name or slogan to signal they claim rights to the mark. Note that you can’t use the registered trademark symbol (®) without federal trademark registration. 

Limitations of Common Law Trademarks

While common law trademarks offer some protection, they have several drawbacks compared to federal trademark registration:

• Limited protection – Rights only apply in areas where the mark is actively used.
• Difficult enforcement – Without a registered trademark, the common law trademark owner may find proving ownership and enforcing rights to be challenging.
• Risk of losing rights – If another business registers the same trademark first, it may gain nationwide priority, forcing the original user to rebrand.

How to Enforce a Common Law Trademark

Even without a registered trademark, businesses can take steps to enforce their common law trademark rights.

How to Prove First and Continuous Use in Legal Disputes

If a competitor starts using a similar mark, the original user must prove they used the mark first and continuously in commerce. Strong evidence includes:

• Dated advertising materials
• Sales receipts or invoices
• Website screenshots
• Customer testimonials

Sending Cease and Desist Letters to Infringers

A cease and desist letter is often the first step in stopping unauthorized use of a trademark. This formal notice requests that the infringing party stop using the mark immediately. While common law trademarks carry less legal weight than registered trademarks, a strong cease and desist letter backed by proof of prior use may be enough to resolve the issue.

When to File a Lawsuit for Trademark Infringement

If an infringer refuses to stop using a trademark, the next step may be a trademark infringement lawsuit. Businesses using common law trademarks can take legal action in state or federal court, but without USPTO registration, the process may be more challenging and costly.

Should you register your common law trademark?

While common law trademarks offer some protection, registering with the USPTO provides significant benefits.

When Formal USPTO Registration Is Recommended

• If a business operates in multiple states or online, a federal trademark offers nationwide protection.
• If a business wants stronger legal standing in trademark disputes.
• If a business wants to prevent others from registering the mark first.

Costs and Benefits of Trademark Registration

While federal trademark registration comes with fees, the long-term protection may outweigh the costs. As of 2025, USPTO filing fees start at $350 per class of goods or services.

How to Convert a Common Law Trademark into a Registered Trademark

To upgrade from common law trademark protection to federal registration:

1. Conduct a trademark search to ensure no conflicting marks exist.
2. File an application with the USPTO through its Trademark Center.
3. Provide proof of use in commerce.
4. Monitor for challenges or opposition during the review process.

Understanding trademark law (things like intellectual property rights, legal presumption, etc.) and conducting trademark searches can be challenging, so many business owners turn to a trademark attorney or a trademark filing service. 

Next Steps

Common law trademarks can offer some protection, but registering a trademark strengthens legal rights and simplifies enforcement. Businesses should monitor their marks, document their use, and consider federal registration for greater protection. It’s also possible to get a state trademark, which is a mark that applies only within the borders of a state. The process of getting a state trademark is less expensive and time consuming than getting a federal trademark.

If you’re relying on a common law trademark, now may be the time to explore trademark registration for broader and stronger protection.g-term business success. If you’re planning to register a trademark, researching trademark classes will help you get it right the first time.