To subscribe or manage your existing subscription, go to this page (or, while logged in to Grapevine, go to More > Settings > Organizer Settings).

Here is how Billing works on Grapevine:

• Your card will be charged as soon as you subscribe.
• Once you have an active subscription, you will see a "Next Payment Date" next to the "Manage Subscription" button. This is the date you will be charged next.
• You can cancel your subscription at any time and you will not be charged again. i.e. If you see a "Next Payment Date" of Feb 15 and you cancel on Feb 14, you will not be charged again.
• You can upgrade to a more expensive plan at any time during the current month's billing cycle and you will be charged the difference between the two plans (i.e. if you are upgrading from a $100 plan to a $210 plan, you will be charged $110).
• You can also downgrade to a less expensive plan at any time, but you will not be refunded, you will just begin being charged the new lower amount when your next payment is due.