When running a test purchase through the checkout page with an error message is returned saying Phone number is required  or  Bill To Zip/Postal Code is required  or  Card Code is required

Solution is returning this error because the form settings are configured in to ensure that these values are passed when a new order is placed. To keep this error from showing up you just need to modify the form settings in to make these values optional. Read this article to learn how to configure the form settings.