An appeals court overturned a district judge’s order that had found New York’s implementation of the pied‑à‑terre tax improper. The higher court ruled that the city had not erred in rolling out the levy. The decision clears the way for Mayor Zohran Mamdani to continue pursuing the tax. It represents Mamdani’s first major legal victory on a key agenda item. The ruling restores the city’s authority to enforce the tax.