Can I purchase more iCloud storage with one annual payment?

Annual iCloud storage plans [Archived document = policy no longer active] - https://support.apple.com/HT201058 - There are now no longer any annual plans, only monthly unless you have a very old plan that is still set to annual payment. If you do not want to add a credit card to your payment information to cover monthly payments, you can try using a gift card to make sure your Apple ID balance has enough money to make payments automatically over a long term. Note though that because this is a subscription, Apple may require a valid payment form such as a credit card be present on the account even though the Apple Account balance will be used first.