You must enter your credit card details when subscribing to a Norton product. Norton automatically saves your card details, so you don't have to fill in the details whenever you want to update your plan. Most of Norton's services are offered as automatically renewing subscriptions to help their customers avoid lapses in their services. If you don't want to renew your Norton subscription, you can do it by canceling the auto-renewal of your subscription, removing the card details from Norton, or through the online form.