Subscription pricing is based on an annual subscription from January to December. Regardless of when you purchase the subscription, you will be charged the full annual subscription price. There are no refunds for cancelled subscriptions. Renewal pricing is subject to change from year to year. Subscription products are delivered via the AER subscription FTP (File Transfer Protocol) server. Subscriptions cannot be charged to an AER account. They can only be paid by credit card (either Visa or Mastercard).