A transit agency’s FinOps policy requires untagged spend to stay below a stated percentage of the monthly bill. Today many new resources launch without the mandatory CostCenter and Application tags. Which strategy best expands tagging coverage for cost allocation and reporting?

A transit agency FinOps policy that caps untagged spend as a percentage of the monthly bill requires expanding tagging coverage, not hiding gaps. Enforce mandatory CostCenter and Application tags with IAM conditions, Organizations tag policies, and AWS Config rules (or SCPs where appropriate), backfill missing tags on existing resources, and track untagged spend until it falls under the threshold. That creates durable cost-allocation hygiene across municipal accounts. Removing all cost-allocation tags from CUR so untagged spend disappears from reports fails because it falsifies the ledger; the waste still exists, reporting merely stops telling the truth. Allowing developers to invent free-form tag keys per ticket without an organization tag policy fails conceptually by producing key sprawl that Athena and Cost Explorer cannot aggregate into reliable showback. Moving every untagged resource into a single quarantine Region to hide it from Cost Explorer fails because Region relocation does not create trustworthy allocation and may break locality, compliance, and latency for citizen services. Exam caveat: exams often offer 'hide untagged spend' tricks; correct answers expand coverage and measure residual untagged percentage. Operational check: publish required tag keys, attach Config noncompliance alerts, remediate backlog with owner tickets, chart untagged spend weekly against the FinOps threshold, and block noncompliant create paths in IAM once the backfill wave completes.