I'm creating something that will have monthly plans. For this example, let's just say there is a "Basic" and "Premium" plan.

Assuming the basic plan has limitations like # of items you can create, etc. Well when you upgrade you can create more, of course. What about if down the road they downgrade?

What do you think is the best way to handle the situation where they now have somehow created something that exceeds the limitations set out in the basic plan?