Pennsylvania Vendor Agreement Template is a legal document. Vendor Registration.There are different types of vendors doing business with the Commonwealth. Us) to complete the four-step supplier registration process. 1. Know about: Information required before drafting the agreement; Essential clauses that need to be covered in an ecommerce vendor agreement. A marketplace vendor agreement is a legal document between a vendor and a marketplace. The agreement contains conditions that the vendor should satisfy in performing a transaction. Here at Enterslice, you can get Vendor Agreement Format. 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. I'm planning on starting an eBay reseller business in Pennsylvania.