An asset purchase agreement is the legal document that will govern the transfer of ownership of a business's assets from the seller to the buyer. Drafting a purchase agreement for buying or selling a business in Texas is a critical step to ensure a smooth transaction.An Asset Purchase Agreement is a legally binding contract between a buyer and a seller that details the terms and conditions of the sale of a business's assets. Selling your business? A Business Purchase Agreement transfers a business entity from its owner to the buyer. A business sale agreement is a legal document that describes and records the price and other details when a business owner sells the business. In an asset sale, the new owner purchases the business's physical assets. The seller retains all rights to the legal entity. Before you buy an existing business, find out if the business owes any Texas taxes.