MPSA is best suited for organizations that want to obtain on-premises licenses of Microsoft software, cloud services, or both on demand, with no enterprise-wide commitment under a single, non-expiring agreement. Software Assurance is optional. We currently use the Volume Licensing Service Center to manage their licenses with Microsoft, and from what I`ve collected, the Business Center is only for customers with a Microsoft Products and Services Agreement (MPSA) that I`m not sure our customer has. Why on earth waste your time asking complete strangers – most of whom struggle with MS licensing agreements – when the first thing you should have done when your customer sent you the email forwards the request to someone in your MSP who will know. How can I make sure? If they don`t have an MPSA, should they just ignore the invitation? and if they have mpSA, what steps do we need to take? Buying short-term subscriptions to certain cloud services will help you meet your short-term needs, for example. B supporting seasonal workers during holiday periods or high volumes on special projects. This flexible purchase option allows you to pay only what you need, when you need it, with higher prices for short-term convenience. You can view your software licenses and cloud services through an MPSA in the Microsoft Business Center. To view software licenses through another Microsoft Volume Licensing Agreement, use the Microsoft Volume Licensing Service Center (VLSC).