A yearly subscription is a billing plan in which a client chooses the amount of credits which will automatically be added to his account at the beginning of each year. The client chooses the amount of credits which is then multiplied by 12. A yearly subscription billing plan extends the credit validity by 1 year + 90 days. The client will be charged automatically each year until he cancels his billing plan. If not spent, credits are accumulated with each purchase. A yearly subscription has a lower per credit price than a one time buy or a monthly subscription.