Subscriptions can be annual. For example, I subscribe to Amazon Prime annually, as it’s cheaper. It renews annually on my anniversary date. If you choose the 12 month sub, it renews annually if not purchased with the sale. It’s around 20 monthly in USD if you choose a monthly sub, OP. You don’t have to buy the prepaid card, but you can for any of the options; one month, one year, or six months.