A flip tax is a fee paid by a seller or buyer on a housing co-op transaction, typically in New York City. It is not a tax and is not deductible as a property tax. It is a transfer fee, payable upon the sale of an apartment to the co-op. Flip taxes are considered a method to help raise money for a co-op's overhead expenses without raising the maintenance fees or assessing flat charge to all residences. Charging the fee to those who are leaving the building seems to be the most politically feasible.