Usage-based pricing is only available on the highest-tiered Team plan (2,000,000 tasks/month). It is automatically enabled when your task usage exceeds the maximum number of tasks. Any additional tasks that your team uses will be added to your monthly rate at the per task pricing of $0.0010.
The way that this works for annual payments is that we charge you the base subscription price at the time of your upgrade (and then yearly), but any costs from extra tasks are charged at the end of every month, when the billing cycle resets.
If you were to choose the Teams 2M plan, then we'd charge you $3499 at the start of the year and then let's say you end up using 2.5M tasks in your first month. We'll charge you $500 at the end of that month ($0.0010/task * 500,000 extra tasks).
If you are on a lower-tiered Team plan (50,000 - 1,000,000 Tasks/month), your Zaps will stop running once your Task limit is reached. In order to keep your Zaps running, you will have to upgrade to a higher-tiered Team plan.
If you plan to store Zaps in your personal account instead of in your Team account and want to use paid features like Multi-Step Zaps or Premium Apps for those Zaps, you’ll need a paid plan for your personal account.