Your subscription will automatically renew at the end of your current subscription period.
If you subscribed using a credit card, you'll receive an email a few days before your next renewal date to notify you that your subscription will soon be renewed.
If you subscribed for an annual subscription using the 'pay by invoice' option, you will receive an email a few days before the subscription is due to expire notifying you your current subscription will soon expire. ON the day the subscription is due to expire a new invoice is sent for your next year's subscription.