Thanks for the reply. I may need some clarification on the relationship of a Mashery Application and a Constant Contact account. The organization I am working with has a 'Constant Contact API: Partner API Access - for Partners ONLY' application.    They have a lot of individual Constant Contact accounts, and they want to share this application with all of them. So for every account they generate a new Access Token through the "Get Access Token" button in Mashery; then login to Constant Contact using that account's credentials.   That all seems to work, we get a new Access Token, but then later when using the API we keep getting errors like "The Mashery account associated with this request is not active, or an invalid" and your earlier reply said "...Access Tokens only one can be available per API Key..."   Is what they are trying to do supported? Can they share the one Mashery Application with many different Constant Contact accounts each having its own Access Token?             ... View more