The property and improvements which the Seller is agreeing to sell and which the Purchaser is agreeing to purchase is known as. Looking to sell your house in New York?Fill out the form below or call us at and get a FREE cash offer! This FSBO paperwork is needed as soon as you accept an offer, so it's useful to have a purchase agreement onhand that you can fill out quickly. Combined Real Estate Transfer Tax Return and Credit Line Mortgage Certificate. List In Suffolk County MLS, Realtor. A For Sale By Owner contract New York must include: 1. The Purchase Price, 2. Commonly Used Forms. Business Certificate Order Form, Fill out and complete the PDF to order a copy of a Business Certificate.