A cloud cost audit should explain what the business is paying for and which changes are sensible. A smaller bill is not useful if it removes backups, reduces required availability or shifts unplanned work onto the team.
Gather the right evidence
Start with billing exports, account ownership, workload descriptions and known business peaks. Identify recurring commitments and services that support more than one product. Make sure the auditor can read cost data without receiving broad deployment permissions.
Ask who owns each material cost. Unlabelled resources and shared services make accountability harder, so correcting ownership information may be an early deliverable.
Separate waste from trade-offs
Unused resources, inappropriate storage retention and oversized test environments deserve investigation. Other spending may reflect genuine reliability or security requirements. Require the auditor to distinguish these cases.
For each recommendation, request an estimate with assumptions, implementation effort and an owner. A headline percentage saving without a resource-level explanation is difficult to act on.
Measure useful unit costs
Choose a unit relevant to the business, such as a completed transaction or an active customer account. Track it alongside total spend so growth is not mistaken for waste. Use consistent time periods and account for seasonal usage.
The AWS Cost Optimization Pillar provides a structured reference. Apply provider-specific recommendations only after checking your own architecture and commitments.
Commission a first milestone that delivers a baseline, ranked opportunities and a safe implementation plan. Ask a cloud specialist to verify savings after changes, including any resulting operational burden.