Fill out your registration form, either by filling in the boxes onscreen or by printing it first and filling out by hand. Once you have the total amount, send the form to the BACS office by email as an attachment (email@example.com) or by post, and you will receive a PayPal invoice in return. To pay the invoice, simply follow the instructions in it. You will receive an immediate receipt for your payment from PayPal, and the office will be alerted that payment has been made. The process is usually very simple and straightforward.