For your APIs, can I upgrade or downgrade plans?

For your APIs, can I upgrade or downgrade plans?

Yes.
You can upgrade, downgrade or cancel at any time. Click on the Billing tab to change your plan.
When you make any of these changes you are subscribing to a NEW plan.
e.g. as an illustrative example, if you change from a plan for $5 which gives you 100 API calls to a plan for $10 that gives you 500 API calls, you will essentially be adding the new $10 plan to your account and canceling the $5 plan.
We will NOT be calculating and providing a difference between the $5 and $10 plan (i.e. you will not be getting an incremental $5 charge and 400 more API calls)