Cost allocation tags are the correct choice because they let you label resources consistently so spending can be attributed to each project across teams and produce monthly chargeback reports.

Cost allocation tags allow you to assign key value pairs such as Project to resources and then use Cost Explorer and the AWS Cost and Usage Report to break down spend by those tags for reporting and chargeback workflows. You must activate the tags for cost allocation in the billing console so the tags appear in reports and billing tools.

AWS Trusted Advisor is not appropriate because it provides best practice checks and recommendations and it does not tag resources or allocate costs for billing reports.

Consolidated billing combines charges across accounts into a single invoice and it can simplify payment, yet it does not label resources or produce per project breakdowns unless tagging is already implemented.

AWS Cost Categories can organize billing data by grouping accounts, tags, or other dimensions to create logical categories, yet it does not apply tags to resources and depends on tags or metadata being present. It is complementary to tagging rather than a substitute.

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