How much will I pay for the upgrade if my plan has not expired yet?

Left unused amount of money from your current plan is deducted from the total price of the plan you want to purchase. This means you will have to pay the difference – you won’t lose your money which you’ve paid for your current plan.

In order to check the status please click “Plan and Billing info” in the top right of your account – you’ll see the total price on the last step before payment.