Mayor Mamdani announced a new rule Wednesday banning hotels from sneakily tacking on extra “resort” or “destination” fees to the price of a stay.

The new rule, adopted by the city’s Department of Consumer and Worker Protection, requires hotels to wrap those fees into the advertised price, and would apply to hotels located in the five boroughs, as well as any hotels advertising in New York City. It also requires hotels to disclose credit card holds and deposits upfront.

“To those who have long approached business as an opportunity to mistreat those who they serve, let today be a warning,” Mamdani said at a press conference announcing the rule at the Whitney Museum. “If you do not change your practices, city government will change them for you. Life in our city does not need to be defined by hardship.”

This action comes as part of a push from the Mamdani administration to crack down on bad actors in the business community. Last week, the mayor announced a lawsuit against delivery app Motoclick.

Mamdani said this new rule is different because the proposal — first put forward under former Mayor Eric Adams’ administration — is now actually being put into law.

“There was a lot of concern that there would be lobbying efforts or efforts to water this down,” Mamdani said. “We’re saying that this rule, this is the strongest hotel consumer protection anywhere in the country — nothing has been watered down at all.”