Organization concept - vedratna/aws-learning GitHub Wiki

For billing purposes, the consolidated billing feature of AWS Organizations treats all the accounts in the organization as one account. This means that all accounts in the organization can receive the hourly cost-benefit of Reserved Instances that are purchased by any other account. In the payer account, you can turn off Reserved Instance discount sharing on the Preferences page on the Billing and Cost Management console for any specific account associated with an organization.
The master account of an organization can turn off Reserved Instance (RI) sharing for member accounts in that organization. This means that Reserved Instances are not shared between that member account and other member accounts. You can change this preference multiple times. Each estimated bill is computed using the last set of preferences. However, take note that turning off Reserved Instance sharing can result in a higher monthly bill.