At AdStage, we bill in advance for both monthly and annual subscriptions. When you upgrade your plan manually, or an auto-upgrade occurs, our payment system finds the differences between the amount you've already paid for your initial subscription and the amount of time on your new upgraded subscription. This amount will be added to your next invoice.
For example, if you're on our Full Suite Pro plan ($1,328/month), and your ad spend exceeds $150,000 fifteen days before your next bill date, you will be auto-upgraded to the Full Suite Elite plan ($1,748 per month). Your next invoice will show a credit for 15 days of unused time on the Pro plan and a new charge for the remaining 15 days on the Elite plan. Since we bill in advance, this invoice will have a charge for $1,748 (30 days) + $874 (15 days), for a total of $2,622.
Moving forward you will be charged the new Elite plan price from there on out (as long as you stay within the subscription requirements).
If you choose to not renew and cancel your subscription, you will retain access to AdStage until the end of your billing period. Any pending prorations will be collected at the end of the period.