Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello Charles,
Monthly and annual plans are considered two separate subscriptions. It doesn't switch from one to another. You will need to cancel one and then sign up for the other.
Please go to https://account.live.com
Sign into your Microsoft account. Then go to Services. Click on "Manage" for the subscription plan you want to cancel.
If you want to cancel the annual plan, you need to contact support to request for refund.
To get help, open the "Get Help" app on your computer (just search for it in the Start menu). or go to https://support.microsoft.com/contactus, Type "Billing" and press Enter. On the next screen, click "Contact support" at the bottom of the page, then choose "Microsoft 365" > "Manage my subscription". You’ll then see the option to chat with a Microsoft support agent who has access to your account to help review the issue.