Resellers must purchase their Customers’ first Microsoft CSP subscriptions on the Cloud Marketplace in order to provision both the plan and a new tenant. For subsequent purchases, you can purchase new subscriptions for an existing tenant through the Reseller Control Panel.
2) From the left-side menu, select the Microsoft CSP option:
3) The ‘Microsoft CSP’ page opens:
4) Scroll down to the ‘Subscriptions’ section and corresponding to the subscription for which you want to find the status for, look under ‘Subscription Status’ - ‘Ready’ indicates that the subscription is ready to use: