For your security, DO NOT write your credit card number or any other sensitive card details on the mailed form. Mailing credit card information is highly insecure and could put your financial data at risk. If a check or money order is not possible and you indicate on the form that you wish to pay by credit card: Our administrators will receive your mailed form with your membership details. They will then call you to securely complete your credit card transaction using a PCI-compliant virtual terminal, ensuring your card details are protected.