A Texas Business Purchase Agreement will help transfer business ownership and outline the terms of the sale. Before an offering or sale of a business opportunity in.Texas, the principal seller must register the business opportunity with the secretary of state. Tex. Creating a purchase agreement is a fundamental part of buying or selling a business in Texas. Fill out the form to access a sample of Practical Guidance. Utilize our Sales Agreement to document the sale of any item, ensuring protection for both the buyer and the seller. Drafting a purchase agreement for buying or selling a business in Texas is a critical step to ensure a smooth transaction.