And most importantly, the document contains the terms, rules, and content that must be followed by the parties. What makes the supplier agreement reliable is the definition of provisions and conditions. Your next document should therefore include the main segments that make an agreement valid. You can also create a checklist to decide which of these clauses you add to your agreement. And without further bluntness, here are the common provisions of a supplier agreement: this is another very important clause, especially for the seller! It should describe not only the amount paid to the seller, but also when they are paid, how they are paid and even what happens in case of non-payment. .