You can upgrade your account at any time by clicking 'Settings' and then 'Account/Upgrade'.  You'll see your current account's size and billing plan, and below that you'll be able to select a new plan. Once you confirm the upgrade, your account will be upgraded immediately, and you’ll be charged the difference in price between your old and new payment plan on a pro-rated basis. At the end of this time period, you’ll be charged your new plan’s stated price. You can find our plan comparison and pricing chart here: Pricing Plans