If you choose to pay online, you must include the credit card fee listed on your invoice. Payments submitted without this fee may result in an additional invoice to recover the balance. Please be aware that not all invoices are eligible for online payment—this may be due to tax-exempt status, or because the invoice total is too high or too low. We are unable to accept credit card payments over the phone. If you have any questions about using this payment option, please contact us before proceeding through PayPal.