Click the “Pay Your Invoice” item below, which will take you to a page where you can enter the amount of your invoice. Once you’ve entered the amount of your invoice, click the “Add to Cart” button. You will be taken to your cart, where you can review the total and click “Proceed to Checkout” at the bottom. You will then be able to finish up the payment process via PayPal (you do not need a PayPal account to pay with a credit card). Or you can mail a check to the address on your invoice.