If your organization is set to pay by Credit Card (rather than invoiced), then Admins in your organization should see a Billing & Plans option in GlassFrog's Admin menu.

Click Billing & Plans to make changes to your plan selections and enter credit card details. You can upgrade to Premium or downgrade to Free. 

Invoice customers will receive emails monthly detailing previous month charges.   Please contact support@glassfrog.com to make changes to the invoicing details or to return to paying by credit card.