The attorney general of Washington, D.C., has filed a lawsuit against a ticket resale platform, StubHub, alleging that the company engages in deceptive advertising practices by promoting low ticket prices and then adding significant fees at the ends of transactions.

The lawsuit filed by Brian Schwalb claims that StubHub’s use of “drip pricing,” which involves adding hidden “fulfillment and service” fees late in the purchasing process, violates consumer protection laws. “StubHub intentionally hides the true price to boost profits at its customers’ expense,” Mr. Schwalb stated.

StubHub defended its pricing practices, stating it complies with legal standards and is consistent with industry norms. The company expressed disappointment at being targeted and voiced support for federal and state measures that would require uniform all-in pricing across all platforms.

“We strongly support federal and state solutions that enhance existing laws to empower consumers, such as requiring all-in pricing uniformly across platforms,” StubHub said in a statement, the Associated Press reports.

According to the lawsuit, StubHub’s online purchasing process often spans more than a dozen pages and uses a countdown timer to create a sense of urgency. This makes it difficult for buyers to discern the true cost of tickets and compare prices effectively. The fees can vary widely and sometimes exceed 40 percent of the advertised ticket price, the lawsuit alleges.

StubHub, based at New York, is one of the largest resale platforms globally for tickets to games, concerts, and other live events. The issue of hidden ticket fees is not new. Earlier this year, the Department of Justice filed a sweeping antitrust lawsuit against Ticketmaster and its parent company, which also addressed the problem of undisclosed fees.