What provenance metadata are required to make carbon ledger entries audit ready

Every entry should carry comprehensive provenance: preparer identity, reviewer/approver, preparation timestamp, data source system ID, raw evidence link (invoice, meter read, telemetry file), calculation method ID, emission factor ID/version, unit conversions applied, organizational boundary rationale, and scope/category classification. Include uncertainty characterization (distribution, confidence interval) and data quality score (temporal, geographical, and technological representativeness) per IPCC data quality indicators. Record data acquisition method (primary vs. secondary), sampling plan, and any transformations. Maintain cryptographic hashes for evidence files to prevent tampering, plus retention schedules aligned with regulatory and assurance requirements. Implement immutable change logs for corrections with reason codes. These elements satisfy typical external assurance tests under ISAE 3410 and internal control frameworks and make recalculation and traceability straightforward. Key Takeaway: Attach identities, evidence, methods, factor versions, classifications, and hashes to each entry; log changes immutably to meet assurance and audit expectations.