AWS provides method for chargeback of shared services

Amazon Web Services (AWS) has released guidance and a sample architecture to help organizations charge back the costs of its AWS Transit Gateway service to the accounts that use it. This new process addresses the complexities of internal cost allocation in cloud environments where central services are shared.

AWS's consolidated billing feature streamlines billing by combining multiple AWS accounts onto a single invoice. While this simplifies management and enhances security, it can complicate internal cost allocation for shared resources like networking traffic or centralized commitments that are billed centrally but used across various accounts.

The new approach outlines a four-step strategy for cost chargeback: first, define the cost units for reallocation; second, calculate the total cost of the shared services; third, choose a distribution logic – either equitable or proportional based on usage; and fourth, gather the necessary data for accurate chargeback.

This strategy can be applied to other shared services, such as centrally purchased savings plans or enterprise support costs. The AWS Transit Gateway example offers a detailed reference architecture and guidance for building an automated chargeback process across multiple regions and user accounts.