Completing and signing this form is Step 1 of the vendor registration process. For Vendors; Vendor Registration.An exclusive vendor agreement protects vendors and their customers from working with a competitor and both sells a service or product in a specified market. We'll help you craft the best vendor contract agreement for your specific needs, and help you manage that relationship as long as you need it. What should be included in a vendor contract? It should include the buyer and vendor's complete addresses and legal names. , choose eContract Philly.