CSRD Buyers' Guide: Third Party Verified Carbon Software (ISO 14064-3)

_A practical field guide for sustainability, finance, and internal audit teams._If you’re preparing for CSRD limited assurance, the question isn’t just “Can our platform calculate Scope 3?” It’s: “Is the calculation methodology independently verified?” Below is a short checklist and a vendor benchmark table you can place straight into your documentation pack.## What counts as third party verification (for software)- Standard: ISO 14064-3 or ISAE 3000/3410 applied to the software/methodology (not merely a corporate inventory).- Evidence: A public verification/validation statement naming the verifier, the scope, and the assurance level.- Traceability: Version/date of the methodology or engine covered, with change log when updated.## Buyer checklist- Public, signed assurance statement naming the verifier- Scope explicitly covers software/methodology (not just client inventories)- Assurance level stated (limited vs. reasonable)- Version and effective date captured in your audit file- Re assurance cadence (e.g., annually or on major changes)## The benchmark table| Vendor | Product or module | Verified? | Standard or level | Verifier | Evidence || ---------— | ---------------------------------------------------------- | :-------: | ------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------— | ------------------------------------------------------------------------------------------------------------------------------ || DitchCarbon | DitchCarbon Portal (Sustainability Information Calculator) | ✓ | ISO 14064-3 (Limited assurance) - Verification Opinion Declaration; plus UL Solutions 'Sustainability Information Calculator Verification' | UL Solutions | UL Solutions Verification Opinion Declaration (June 6, 2025) & program verification (June 10, 2025) || CarbonChain | Corporate & product footprint methodologies | ✓ | Validated/verified as aligned with GHG Protocol | SGS (validation), Bureau Veritas (verification) | https://www.carbonchain.com/blog/carbonchain-methodology-receives-third-party-verification || Lune | Carbon calculation tool | ✓ | Verified against applicable clauses of ISO 14064-1 | Interface NRM Ltd | https://docs.lune.co/lune-climate-iso14064-verification-statement.pdf || Persefoni | GHG accounting methodology (software) | ✓ | ISO 14064-3 (Limited assurance) - methodology validation only (excludes corporate inventory) | Apex Companies | https://persefoni-production.s3.us-east-2.amazonaws.com/docs/GLG_Persefoni_Independent_Validation_Statement.pdf || Watershed | Carbon Data Engine | ✓ | ISO 14064-3 (Limited / 'moderate' assurance) | Apex Companies (independent validation) | https://storage.googleapis.com/tech-docs-watershed/Watershed-Validation-Statement-20231127.pdf |## How auditors read thisAuditors will ask: what exactly was assured, by whom, and when? Make sure your methodology version in use matches (or post dates) the verification statement and that any material updates are either covered by an updated statement or appropriately documented.## Risk notes for CFOs & audit committees- Model drift: If factors or logic change, confirmation of continued assurance coverage is prudent.- Supplier data quality: Verification of the calc engine doesn’t replace supplier data controls; track those separately.- Disclosure clarity: In filings, describe the role of your software and the scope of its independent verification.---