Sure! You must be logged in to your Yapp account.
If you are on our pricing page and want to upgrade, simply choose the plan you want to switch to and click the "Upgrade" button. This will then take you to the same Upgrade screen as above.
When you choose to upgrade, you'll be charged a prorated amount for the remainder of the year on your new plan, minus a credit for the remaining time on your old plan. Both are calculated depending on when your initial plan began and are laid out on the checkout page before you pay.
Your upgrade will be charged to the card on file in your account. You can edit your payment information on your account settings page.
Under "Billing," you'll see a "Change Plan" button. Click on that and you'll be taken to the upgrade page with a automatically updating pricing calculation.