When you change your plan we immediately transfer all funds already paid and unused to your new subscription, and you are only billed when existing funds are used up.
For Example:If 15 days ago you purchased a Pro subscription for $9.95, you have approximately $5 left to use. Changing today (day 15 of Pro) to Master for $19.95 you are immediately upgraded, and are charged for another month after 8 days (5 / $19.95 of a month).
Please note, for a short time this will differ for upgrades paid through FastSpring. Currently, if you upgrade your subscription via FastSpring, you will be charged immediately for the upgraded subscription. The use of remaining funds listed above still applies like usual.
We make sure to have account changes instantaneous and simple and straightforward, you get what you pay for, no matter which plans you change between.
Go to Paid Plans for a list of possible upgrades.