The big advantage of creating a new member account inside your master organization account is to consolidate billing for all member accounts in one place, your master S3 bucket.
You must have a AWS Organization master account set up.
- Go to the AWS Organizations console at https://console.aws.amazon.com/organizations.
- Login using the credentials for the master organization account.
- On the AWS Organizations page, click Add Account.
- Select Create Account. Enter the required details and click Create.
The owner of the AWS Organization master account (listed under Account Name) has administrator privileges for all new member accounts. The owner of the new member account (listed under Email) has administrator privileges only for the new member account.