Sign in to the AWS Management Console as the root user
Open the AWS Billing and Cost Management console
Go to Account
Review and cancel any active AWS services or resources
Back up any data you want to keep
Close all AWS Marketplace subscriptions if applicable
Check for any outstanding charges and pay them
Select Close Account
Confirm account closure by following the on-screen prompts
Save the confirmation email for your records
Contact AWS Support if you need help with the closure process