The average co-op apartment flip tax in NYC is 1% to 3% of the sale price, and it’s customarily paid by the seller. Exact flip tax amounts vary by building. A flip tax can be structured as a percentage of the sale price, a percentage of profits, a flat-fee or a per-share amount. A co-op’s flip tax is typically outlined in the proprietary lease, by-laws and/or the resale application.