At the time you upgrade to a dlvr.it premium account, we'll bill your card for the full monthly plan rate.
Then on subsequent months on or about the same calendar date, we'll again bill you the monthly plan rate.
So for instance, if you upgrade your dlvr.it account plan on the 16th of the month, we'll bill you the monthly plan rate on (or about) the 16th of each month.
You can view billing history detail by navigating to the Payment History tab on the left side of your Account Settings.