To update your credit card information, simply login and click your name in the top right corner to get to your accounts settings page.
Once on your account settings page, either click on the "credit card" link as shown below, or if unavailable, then click on the "subscriptions" link as shown in the following picture.
Or click "subscriptions" if credit card link unavailable:
Proceed to update your card information and click save.
*Please note: You must be the "Admin" for your firm in order to access the credit card update link.