Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
If you have an active subscription which is associated with the account you want to close, first cancel the subscription. Then see https://support.microsoft.com/en-us/account-billing/how-to-close-your-microsoft-account-c1b2d13f-4de6-6e1b-4a31-d9d668849979.