The collective action is being led by Hotrec, the European umbrella organisation for the hospitality sector. Chairman Alexandros Vassilikos said hotels had “suffered for years under unfair conditions and excessive costs,” and that it was now “time to stand together and demand redress.”

The hotels claim they were forced by Booking to accept contract clauses that barred them from offering lower prices on their own websites or through other platforms.

Booking rejected the allegations last month with a spokesperson saying the claims are based on a misinterpretation of previous rulings, and dismissed suggestions that Booking had artificially raised prices as “nonsense.”

In a 2024 ruling, the European Court of Justice said such restrictions could be unnecessary and reduce competition, although it also stated that parity clauses were not automatically in breach of EU law.

The Amsterdam-based platform, founded in the Netherlands in the 1990s, has since dropped the practice in Europe. Under the Digital Markets Act, which came into force last year, parity clauses are no longer permitted for dominant online platforms.

The Dutch consumers’ association Consumentenbond is also preparing legal action on behalf of customers.

It argues Booking earned around €1 billion as a result of so-called “dark patterns”, using fake discounts, incomplete pricing and made up scarcity.

Booking told Dutch News at the time that the company has “always fought to provide the best possible prices and transparent booking experience to travelers and strongly contest any allegations to the contrary.”