Most trademark owners know they need to renew their registration every ten years. Fewer are aware of a filing that can make their trademark significantly harder to challenge over time: the Section 15 Declaration. For brands that have built consistent, long-term use of their marks, this declaration is one of the most strategically valuable steps in trademark portfolio management.
Understanding Section 15 of the Lanham Act
Section 15 of the Lanham Act — the federal law governing trademark registration in the United States — allows a trademark owner to apply for a legal status known as incontestability. This status is not automatic. It must be earned through five years of substantially exclusive and continuous use of the mark in commerce after registration, and claimed by filing a formal declaration with the USPTO.
The trademark section 15 declaration is filed at the USPTO and typically combined with the Section 8 Declaration of Continued Use, which is required between the fifth and sixth year of registration. Filing both together is efficient and ensures that the mark’s maintenance timeline is kept on track.
What Incontestability Actually Means
Incontestability does not mean the trademark cannot be cancelled under any circumstances. What it does mean is that certain grounds for challenging the trademark’s validity can no longer be raised against it.
Once a trademark becomes incontestable, the following challenges are no longer available to third parties:
The mark is merely descriptive. Before incontestability, a competitor could challenge registration on the grounds that the mark simply describes the goods or services it represents. After incontestability, this argument is foreclosed — even if the mark was arguably descriptive when it was originally registered.
Prior use by a third party. Certain prior use arguments that could be raised against a non-incontestable mark become unavailable once the five-year requirement is met and the declaration is filed.
The practical effect is that the trademark becomes significantly more defensible. Parties who might otherwise challenge the mark’s validity during a dispute lose important legal avenues once incontestability attaches.
What Incontestability Does Not Protect Against
The Lanham Act specifies several grounds on which an incontestable mark can still be challenged. These include:
The registration or incontestable right was obtained through fraud.
The mark has been abandoned by the owner through non-use.
The mark is being used to misrepresent the source of goods or services.
The mark is a functional element — meaning it is essential to the use or purpose of the product, rather than a source identifier.
The mark was used to violate antitrust laws.
The mark is generic — a term so common that it refers to a category of products rather than a specific source. Generic marks receive no trademark protection regardless of incontestability.
The Requirements for Filing a Section 15 Declaration
To qualify, several conditions must be met. The mark must be in continuous use in commerce for five consecutive years after the registration date. The mark must not be the subject of a pending or decided adverse decision concerning the registrant’s rights. There must be no pending proceeding involving these rights before the USPTO or the courts.
The declaration itself requires the trademark owner to identify the registration, confirm the continuous use requirement, list the goods and services for which the mark is in use, and state that there has been no final adverse legal decision during the five-year period.
When to File and Why Timing Matters
The Section 15 declaration can be filed any time after five years of continuous use following registration — there is no requirement to file it at the five-to-six-year maintenance window. However, most trademark owners file it simultaneously with the required Section 8 declaration at that point, since the paperwork overlaps and the five-year threshold typically aligns with the first maintenance deadline.
There is no deadline for filing a Section 15 declaration other than the need for five years of continuous use. An owner who missed the opportunity to file alongside their Section 8 can still file at any later point, provided the use and legal requirements are satisfied.
Section 15 vs. Section 8: Understanding the Distinction
These two filings are often discussed together but serve different purposes. The Section 8 declaration is mandatory for maintaining the registration — without it, the registration is cancelled. The Section 15 declaration is optional — it carries no maintenance function but confers the incontestability benefit.
Filing both together is standard practice and administratively efficient. But it is important for trademark owners to understand that the Section 8 filing is not optional, while the Section 15 filing, though highly advantageous, is a choice.
Conclusion
A Section 15 declaration converts an already-valuable trademark registration into a more durable legal asset. For any mark that has been in continuous use for five or more years, filing the declaration should be a standard part of the trademark maintenance process — not an afterthought. The stronger the brand, the more it is worth protecting with every available tool.
