all of our legal contracts and documents are drafted and regularly updated by licensed attorneys. all of our legal contracts and documents are drafted and regularly updated by licensed attorneys. all of our legal contracts and documents are drafted and regularly updated by licensed attorneys. if you need to record a business transaction between two parties then you can use a purchase order. a purchase order is a written document that records a business transaction between two parties — the buyer and seller. once a seller accepts the order, a legally binding contract is formed between the buyer and seller. if you are buying a large number of products or many types of products, you should use it to formally document what is being purchased for your business. a purchase order is a written authorization from a buyer to acquire a lot of goods or services.