Elf Labs wins permanent trademark protection after Supreme Court cert denial

The Federal Circuit’s ruling in Curtin v. United Trademark Holdings sets a binding standard for who can challenge a registered character trademark

When the US Supreme Court declined to hear the petition in Curtin v. United Trademark Holdings on April 20, 2026, it made permanent a binding Federal Circuit standard defining who can challenge a registered trademark in the United States. This has direct implications for every company that has built and commercialized a character IP portfolio.

United Trademark Holdings, parent entity of Elf Labs, is the Miami-based entertainment studio behind one of the world’s most commercially developed fairy tale character portfolios. The case originated when a third-party petitioner challenged Elf Labs’ registered RAPUNZEL trademark at the Trademark Trial and Appeal Board. The challenge proceeded through the TTAB and the Federal Circuit, both of which sided with United Trademark Holdings and dismissed the opposition. Holland & Knight LLP, retained to oppose the cert petition, successfully argued against Supreme Court review. The court’s April 20 denial made those protections final, permanent, and binding.

The legal standard at stake

The Federal Circuit applied the zone-of-interests test from Lexmark International v. Static Control Components to administrative trademark proceedings, a meaningful doctrinal extension. The court held that the Lanham Act’s opposition process exists to protect commercial interests, not downstream consumer concerns. A petitioner must now demonstrate a genuine commercial stake to have standing. 

“The court drew a clear line,” said Thomas Brooke, a partner at Holland & Knight LLP and lead counsel in the case. “The trademark opposition process exists for parties with genuine commercial stakes, not as an open channel for any challenger.” Appellate attorney Ilene Pabian and IP attorney Sadie Mlika, also of Holland & Knight, carried the matter through the Federal Circuit and the SCOTUS petition stage alongside Brooke.

What it means for brand owners

Before this ruling, the zone-of-interests standard had not been applied uniformly to TTAB opposition proceedings, leaving an opening that consumer advocates and public interest challengers had used to contest registrations on grounds commercial competitors would not have standing to raise. That opening is now closed. Any company that has invested in building a registered character portfolio benefits from a materially higher bar against third-party opposition, which Brooke described as “real, durable certainty” for companies that have commercialized their portfolios.

The portfolio at the center of the case

At issue was Elf Labs’ portfolio of more than 500 registered character assets, including original interpretations of Rapunzel, Cinderella, Snow White, and The Little Mermaid. These are not claims to the public domain source material but registered protections for the company’s own original creative interpretations of classic fairy tale figures, commercialized across licensing, animation, consumer products, and immersive entertainment over more than a decade. The portfolio has generated more than $15 million in royalties across 30+ countries and forms the legal foundation of the company’s commercial operations. The company has reserved the Nasdaq ticker symbol ELFS.

Looking ahead

The cert denial clears the runway for Elf Labs’ next phase. The company is entering pre-production on its first animated feature film with theatrical distribution secured in China for the Chinese New Year window, the most commercially significant release period in a market with more than 90,000 screens. 

The cert denial in Curtin v. United Trademark Holdings answers a question practitioners have been navigating around for years. Companies that have built registered character portfolios now know the opposition process cannot be weaponized by parties with no commercial stake in the outcome.

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