All invoices are to be delivered to the address indicated in the purchase order. An MSA, or Master Service Agreement, is a contract between a company and a vendor that outlines the terms and conditions for services the vendor will provide.THIS MASTER EQUIPMENT LEASE-PURCHASE AGREEMENT (this "Master Agreement") is made as of. Must get an attorney to form the master lease agreement. An MSA is a contract between two or more parties that establishes what terms and conditions will govern all current and future activities and responsibilities. The termination of this Agreement does not terminate any Sales Confirmation executed pursuant to this. Agreement. 1.4 Billing and Payment.