In a unanimous decision, the U.S. Supreme Court held this week that trademark tacking is an issue of fact to be addressed by the jury, and not a question of law to be addressed by judges.

The doctrine of trademark tacking lets a mark holder ‘tack’ the use of a pre-existing mark to a new mark with respect to priority of use; this allows a mark holder to modify its mark over time without losing that priority. The doctrine is available in situations where the two marks in question are similar enough to be deemed “legal equivalents”. Said another way, the newer mark cannot be materially different from the older one, but must extend the preexisting commercial impression of the older mark. The question presented before the Court was whether it should be the jury or the court who makes this determination.

As Justice Sotomayor stated in her opinion, “[b]ecause the tacking inquiry operates from the perspective of an ordinary purchaser or consumer, we hold that a jury should make this determination… [The] application of a test that relies upon an ordinary consumer’s understanding of the impression that a mark conveys falls comfortably within the ken of a jury.”

This decision does not change the law with respect to what constitutes trademark tacking; what it does, however, is increase the cost of asserting a trademark tacking claim or defense. Arguments presented to juries are far more expensive and difficult to prepare than those presented to judges, so litigants who seek to slow down the pace or increase the cost of trademark litigation will welcome the Hana Financial decision. Likewise, even though the Supreme Court recognized that judges could still rule on trademark tacking claims in the context of, for example, a motion for summary judgment, the Court’s holding sends a signal to judges that, when in doubt, they should deny the motion and let the jury decide at trial.

The case is Hana Financial Inc. v. Hana Bank, case number 13-1211, in the Supreme Court of the United States.