Before the Trademark Trial and Appeal Board (TTAB), expert witnesses aren’t used nearly as often as they are in federal court. But when they are used strategically—and correctly—they can make a critical difference in the outcome of a case. Whether it’s establishing fame for dilution claims or interpreting consumer perception in a descriptiveness dispute, expert testimony can give litigators an evidentiary edge. Still, experts in TTAB proceedings come with their own risks, timing constraints, and procedural pitfalls.

For most practitioners, the TTAB is seen as a paper-heavy, documentary-driven forum. That perception is largely true. The Board rarely hosts live testimony, and cases are typically resolved based on written records and stipulated facts. However, the rules of practice do not prohibit expert evidence, and in certain disputes—especially those involving survey data or niche industry insights—an expert witness can become a powerful tool when the legal and factual issues demand more than lay opinion.

When TTAB Cases Call for Expert Testimony

One of the most important things to understand about using expert witnesses at the TTAB is knowing when they are actually helpful. Experts are best suited for matters where specialized knowledge is necessary to prove or explain a key issue. For instance, in a dilution proceeding, the TTAB requires evidence of fame that is recognized across a significant portion of the U.S. public. A qualified expert in brand recognition or consumer marketing may be able to present survey data or marketing analysis that supports such a claim.

Likewise, in cases involving descriptiveness, genericness, or acquired distinctiveness, expert linguists or market analysts may help demonstrate how a term is perceived by the relevant public. In some industries, the Board has accepted expert insight on how trade terminology is understood by practitioners or consumers within that field.

Trademark practitioners sometimes also use experts to testify about the commercial impact of a term, consumer confusion in the marketplace, or the comparative strength of third-party marks. However, such testimony must be carefully crafted to meet evidentiary standards, and practitioners must ensure that the expert’s conclusions are supported by actual data or industry experience.

How TTAB Treats Expert Disclosures

Unlike federal courts operating under the Federal Rules of Civil Procedure, the TTAB follows a modified system under its own rules and practices. Nonetheless, the basic expectations for expert disclosure are similar. According to TTAB Tips and the Trademark Board Manual of Procedure (TBMP), parties intending to use expert witnesses must make timely disclosures under Rule 2.120(a)(2). These disclosures must be served by the deadline set in the scheduling order, typically before the close of discovery.

An expert disclosure must identify the expert and include a summary of the expected subject matter of their testimony. If the expert has prepared a written report, it must be provided to the opposing party. Importantly, if these disclosures are late or incomplete, the expert may be excluded from the record. The Board has consistently emphasized that surprises and sandbagging are not tolerated.

TTAB judges have also clarified in past TTAB Tips that an expert disclosure must allow the other side a fair opportunity to conduct discovery, including a deposition of the expert. Since Board proceedings are mostly paper-based, practitioners must plan early if they want to accommodate the additional time, cost, and procedural complexity that comes with introducing expert testimony.

Strategic Risks in Using Expert Witnesses

While expert witnesses can strengthen a case, they also introduce significant risks. First and foremost is cost. Many TTAB cases are filed by small businesses or individual applicants who simply can’t justify the expense of retaining an expert, especially when the value of the disputed mark is modest. Even for larger parties, the ROI must be considered. Experts often require support staff, exhibit preparation, and testimony coordination. At the TTAB, which is a limited forum without monetary damages, those investments must be carefully justified.

Another major risk is that an expert’s testimony may be excluded altogether if it is not timely disclosed or does not comply with TTAB rules. The Board has no obligation to allow extensions or corrective amendments when a party misses its expert deadline. Moreover, if the expert relies on surveys or methodology that is unreliable or prejudicial, the other side may file a motion to strike the evidence altogether. This can result in wasted time, costs, and reputational harm to counsel.

There is also the strategic concern that using an expert may actually complicate a case unnecessarily. TTAB judges are seasoned in evaluating likelihood of confusion, descriptiveness, and acquired distinctiveness without expert testimony. If a case can be proven using simple commercial evidence, TESS records, and declarations from company executives, then adding an expert may appear excessive or even weaken the party’s position by overreaching.

Best Practices from the TTAB Tips

The July 2020 TTAB Tips document offers several important reminders regarding expert witnesses. One of the clearest takeaways is that early planning is essential. Counsel should identify early in discovery whether expert support is needed, and if so, serve the proper disclosures in time to allow the other side to respond appropriately.

Another key tip is to be specific. Simply disclosing that “the party may call an expert to testify about consumer perception” is not enough. The Board expects clear identification of the witness, the subject matter of their testimony, and the supporting data that will be relied upon.

Practitioners should also remember that TTAB judges are generally not impressed by overreliance on expert jargon or voluminous appendices. The testimony must be focused, probative, and tied directly to the legal standards relevant in the proceeding. Irrelevant or vague conclusions are likely to be given little weight or struck from the record.

Finally, counsel must coordinate expert testimony with trial procedures. Since most TTAB trials are conducted through written declarations rather than live witness examinations, expert declarations must be carefully drafted to withstand scrutiny. All underlying exhibits, data, and methodologies must be included in the trial record. Failure to do so can render the testimony inadmissible, even if the expert is qualified.

Conclusion: Is It Worth It?

Expert witnesses at the Trademark Trial and Appeal Board remain rare for a reason: they’re expensive, procedurally sensitive, and often unnecessary for straightforward disputes. But in the right case—with the right timing and subject matter—they can be the key to winning a contested matter or overcoming a difficult legal standard.

For trademark attorneys who understand the strategic tradeoffs and procedural requirements, experts can be a valuable (if underutilized) tool in the TTAB toolbox. But for those who dive in without planning, they risk adding cost and complexity to cases that could have been won through simpler means.

As always, success at the TTAB depends not just on the strength of your argument, but on your command of the rules, your respect for process, and your ability to use every tool—from ESTTA to expert witnesses—wisely.