What does an automatic upgrade cost on an annual plan?

The prorated amount is charged to your card on the day the upgrade takes effect. It covers the rest of your current paid period. Your renewal date does not change — your next invoice falls on its normal date and carries the new plan’s full rate.

The amount is the difference between the two plans for the period remaining. For example: on annual Starter ($79/year), upgraded to Growth ($149/year) six months in, roughly half the difference — about $35 — covers your remaining six months. Your subscription then renews at the full Growth annual rate ($149) on your existing renewal date.

The upgrade email is a receipt: it names the amount charged, what period it covers, and when your next full renewal falls.