To update your existing credit card information, or add a new credit card, for specific subscriptions from within your Untappd for Business account, you can do so from the Billing & Invoices screen.
Click the down arrow next to your name in the upper right hand corner and select Billing & Invoices from the dropdown menu:
Click the location you would like to update credit card info for in order to access the Subscriptions home screen, then click Subscriptions.
Click View on the subscription you'd like to update a payment method for:
Click the Pencil Icon next to Payment Method:
Choose to update the payment method of all subscriptions or just the selected subscription, then click Continue:
Select your new payment method, then click Update: