The Washington residential purchase and sale agreement is a legally binding contract between the seller of residential property and a buyer that transfers property from the former to the latter. The completed document will describe the property being sold, purchase price, closing date, and closing costs.

If additional property will be included with the sale, or if the seller requires certain financial or insurance obligations to be fulfilled for the deal to go through, these terms must be included in the agreement as well. Both parties can negotiate and amend the contract until they are in agreement. However, once they both have executed the document, they will be legally bound to its terms and conditions.