A company that has multiple AWS accounts is using AWS Organizations. The company’s AWS accounts host VPCs, Amazon EC2 instances, and containers. The…

The most precise source of chargeable usage is the AWS Cost and Usage Report (CUR). For resources in an AWS Organization, a user-defined tag must be activated in the management (payer) account before it appears in all member accounts’ cost data. After activation, the consolidated CUR that the management account creates and stores in an S3 bucket contains line-item costs broken down by that tag, allowing the company to sum the costCenter = compliance lines and cross-charge the compliance team accurately.

B. Member accounts cannot activate cost allocation tags; separate CURs and a Lambda aggregation add unnecessary complexity and possible inaccuracies.
C. Tag activation must be done in the management account, not in members; otherwise the tag data will not appear in the CUR.
D. Trusted Advisor provides optimization checks, not detailed cost reports by tag; it cannot generate a billing summary filtered on user-defined tags.

1. AWS Billing and Cost Management User Guide – “Activating user-defined cost allocation tags” (Only the management account can activate tags for the organization) – 2023-11-15, Section “Cost allocation tags”.

2. AWS Cost and Usage Reports User Guide – “Using Cost Allocation Tags in CUR” (CUR includes tag columns once activated) – 2023-10-05, Paragraph 2.

3. AWS Organizations Documentation – “Consolidated Billing and Cost allocation tags” (Tag activation in payer account applies to all member accounts) – 2023-09-12, Section “Sharing cost data across the organization”.