The easiest way to create a Business Purchase Agreement is to use a template that is customized to your state. When buying the assets of a business, some are subject to sales or use tax, while others are not.Items subject to retail sales tax. A business sale agreement is a legal document that describes and records the price and other details when a business owner sells the business. Utilize our no-cost Business Purchase Agreement to document the sale of a business. The general rule is that contracts do not need to be in writing. The exception would be the contracts falling under the statute of frauds. Statewide contracts leverage the state's collective buying power to help you save money, reduce risk, and streamline purchasing. A business purchase agreement is a legal contract specifying terms for buying or selling a business, including conditions and obligations. A real estate contract washington is, at its core, a legally binding agreement made between two or more parties in a Washington real estate deal.