Processing. Please Wait.

Our free account and tools will help you get started and maintain your business. All for free. Enter your information below to create your free account.

  • Minimum 8 characters long
  • At least 1 capital and lowercase letter
  • At least 1 number
  • At least 1 special character

Free Download


Choose to view the in another tab or to download the PDF.

Common Law Trademark Infringement

When You Want More

Common law trademark infringement refers to a trademark violation where one or both marks are unregistered. Whether it is done on purpose or accidentally, trademark infringement can undermine businesses, confuse consumers, and result in legal action.

Trademark infringement occurs when a mark that is too similar to another is used to sell related products, potentially causing consumer confusion about who is providing the good/service. Because they are not in any official trademark database, infringement against common law trademarks could happen more easily and be trickier to manage than other trademark infringement.

In this article, we'll cover:

What Is Common Law Trademark Infringement?

A common law trademark is an unregistered word, image, design, or phrase used to differentiate one brand from another in a specific geographical region. Because a trademark’s main purpose is to help consumers tell businesses and products apart, avoiding infringement (or enforcing your own trademark rights) is one of the most important parts of maintaining a common law trademark.

Common law trademark infringement occurs the same way that registered trademark infringement occurs: a business (knowingly or unknowingly) takes another business’ trademark and uses it to sell similar products. This can include exact replicas, like with counterfeits, but usually centers on marks that are similar enough to have likelihood of confusion.

The main difference when discussing common law trademark infringement versus registered trademark infringement is that common law trademark infringement – you guessed it – must include common law trademarks. This includes a common law trademark infringing on a registered mark, a registered mark infringing on a common law mark, or a common law mark infringing on another common law mark.

Trademark Infringement: Common Law vs. Registered

Generally, a registered trademark and a common law trademark follow the same basic principals – existing for consumers to tell goods/services apart, being unique in their jurisdiction and industry, and having the ability to enforce their mark if another business infringes upon it.

Still, there are differences between common law trademarks and registered trademarks that are important to keep in mind, especially in relation to infringement.

  • Where the Mark Is Enforced

Common law trademarks have protections in the business’ area of operation whereas registered trademarks have protections in the region where they are registered, whether that’s statewide or federal.

  • How the Mark Is Enforced

If the owner of a federally registered trademark realizes that another business is infringing on their mark, they have the right to sue in federal court. Common law trademarks do not have this option. They can sue for infringement in state court, but no higher.

Additionally, federally registered marks can sue for damages caused by the infringement, while common law marks can only sue to stop the infringement from continuing.

How can you tell if your mark is infringing?

While two different businesses offering completely different goods/services might have similar or even identical trademarks, if you are causing any likelihood of confusion, then you are committing infringement. Here’s a few common law trademark infringement scenarios to consider:

  • Common law trademark infringing on a registered mark:

If your common law trademark infringes on a registered mark, that means your mark was used in commerce after the other mark was registered.

  • Registered trademark infringing on a common law mark:

If your registered mark is infringing on a common law mark, don’t assume your formal registration will make the case a slam dunk. (See the case study below!)

  • Common law trademark infringing on a common law mark:

Though it can be trickier than this, a good rule of thumb is that whichever business used their trademark in commerce first is likely the rightful owner.

Keep in mind: If you have a common law trademark in Arizona and it is identical to a common law mark in New Jersey, this is likely NOT infringement, even if both companies sell similar products. Since common law trademarks only have rights in their area of enforcability, two common law trademarks across the country are unlikley to be infringing on each other.

Can you prevent someone from infringing on your common law mark?

Since common law trademarks are not registered in any official database, prevention comes down to how proactive you are. For example, you can make sure your mark is available online rather than just in person, which would help others find it if they are conducting a clearance search.

You can also keep an eye on other trademarks being used. This includes looking at common law marks in your area and scouring the USPTO’s Trademark Electronic Search System (TESS) to keep up with what marks are pending nationally. This practice, called trademark monitoring, can also include looking through state databases, keeping up with domain registries, and looking through social media.

What can you do if someone infringes on your common law mark?

If you notice someone is infringing on your common law trademark, you can enforce your common law trademark rights. This can include sending a cease and desist letter and even suing the infringing party to prevent further use of the trademark. You can also oppose a trademark application that’s pending registration with the USPTO.

Do registered trademarks always win infringement cases?

The winner of a trademark case does not always go to the registered mark. While registered trademarks certainly have advantages, such as officially documented first use and the ability to sue in federal courts, they are not invincible. The mark that wins in an infringement case is usually the one that can prove they had first use of the mark, though other factors can come into play.

Below is a look at a real world infringement case that demonstrates how common law trademarks can win against registered marks.

Have a trademark you’re ready to register? Get started with Northwest’s Trademark Service today!

Real World Common Law Trademark Infringement

One example of real world common law trademark infringement is the case of NetJets Inc. v. IntelliJet Grp., LLC. NetJets, with a federal trademark registration, sued IntelliJet Group, who had common law trademark rights, for trademark infringement.

In this case, the common law trademark was able to prove its validity against the might of a federally registered trademark. Let’s go over what happened, how the courts responded, and what this means for you.

What happened with NetJets vs. IntelliJet?

NetJets Inc, formed in 1992, had an internal software called INTELLIJET that was used to help run their business. NetJets submitted INTELLIJET for trademark registration with the USPTO. In 2002, NetJets filed a “declaration of use and incontestability” for certain irrefutable rights. The USPTO approved this.

In 2005, a company called IntelliJet Grp., LLC was formed. As a broker for privately owned aircrafts, IntelliJet used their business’ name as a common law trademark in Florida. The founder of IntelliJet conducted a trademark clearance search and saw NetJets’ INTELLIJET trademark on the USPTO’s trademark database. However, since NetJets used the word for software and IntelliJet used it for their aircraft brokerage service, the founder thought there was no likelihood of confusion.

The owners of NetJets thought differently.

In 2012, NetJets filed a lawsuit against IntelliJet, including a claim of trademark infringement under the Lanham Act and under Ohio common law.

IntelliJet responded with a counterclaim. This claim said IntelliJet did not infringe upon NetJets’ trademark and suggested NetJets’ USPTO registration for INTELLIJET should be voided because the mark was not being used in commerce when the “declaration of use and incontestability” was issued.

What were the case findings for NetJets vs. IntelliJet?

The Sixth Circuit Court of Appeals issued an opinion that found IntelliJet was not infringing on NetJets’ trademark. The case was sent back to the original Ohio district court for a final ruling, which ruled in IntelliJet’s favor.

The appeals court decided:

  • NetJets’ mark was NOT a service mark under Ohio common law because the software was a “conduit” to provide services, not the service itself.
  • There was no likelihood of confusion because “the realities of the marketplace suggest that the markets between NetJets and IntelliJet’s products are … distinct, and the consumers [are] sophisticated.”

In conclusion: IntelliJet’s common law trademark defeated the infringement claims partly because their mark was being used in connection to their service and the other mark, though federally registered, was not as closely connected to its registered use. Despite NetJets’ filing and getting approved for incontestable entitlement to the mark, IntelliJet was able to prove that their mark did not infringe on NetJets’.

What does this ruling mean for your mark?

Common law trademarks often face a tough, uphill battle when against a federally registered trademark in an infringement case. But as IntelliJet proved, conducting a thorough clearance search in the begining and documenting your use in commerce can go a long way.  Common law trademark infringement can be tricky to navigate, but it’s not impossible.

At the end of the day, how thoroughly you prepared before using your common law mark in commerce can have a lot to do with how well you fare.

When You Want More