Scope 3 Carbon Software: Verification League Table (2025)

_Who passes independent verification, and who doesn't (yet)._This league table focuses only on third-party verification/validation of software methodologies used to calculate Scope 3 emissions. No points for "audit-ready," security certs, or corporate inventory verifications.## Scoring rules (simple and fair)- Verified (✓): Public third-party statement covering the software/methodology, naming the verifier and assurance level (ISO 14064-3 or ISAE 3000/3410).- No Public Verification (–): No public software-level statement found.- Notes: Include the statement date/version so readers can check recency.## The table| ✓/– | Vendor | Product or module | Standard / level | Verifier | Evidence | Assurance date || :-: | --------------------------------- | ---------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | ------------- || ✓ | 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) | 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 | - || – | CO2 AI (BCG) | Corporate & product footprinting | States adherence to PACT/PEF/ISO 14067/14044; SOC 2 & ISO 27001 (security) | - | https://www.co2ai.com/blog/co2-ai-unveils-the-first-solution-to-compute-product-footprints-at-scale | - || – | Carbon Interface | Emissions API | - | - | No public software level assurance statement found (as of 2025-10-12) | - || – | Climatiq | Emission factors & API | States 'scientifically vetted' emission factors; methodology hub | - | https://www.climatiq.io/methodology | - || – | EcoVadis | Ratings & Carbon Action Module | External methodology committee review (not formal assurance) | External committee (advisory) | https://support.ecovadis.com/hc/en-us/articles/115002531507-What-is-the-EcoVadis-methodology | - || – | Gravity Climate | Carbon & energy management platform | Positions as 'audit friendly'; customers pass audits | - | https://www.gravityclimate.com/blog/june-2025-product-updates | - || – | IBM (Envizi) | Envizi ESG Suite | - | - | https://www.ibm.com/products/envizi | - || – | IBM EIS GHG APIs | Environmental Intelligence Suite - GHG APIs | - | - | No public software level assurance statement found (as of 2025-10-12) | - || – | Manufacture 2030 | M2030 Platform | - | - | No public software level assurance statement found (as of 2025-10-12) | - || – | Normative | Carbon Accounting Methodology | - | - | No public software level assurance statement found (as of 2025-10-12) | - || – | OpenCO2 (CO2API) | Emission Factors API | - | - | No public software level assurance statement found (as of 2025-10-12) | - || – | Plan A | Platform & Methodology | - | - | No public software level assurance statement found (as of 2025-10-12) | - || – | SAP | Sustainability Control Tower | - | - | https://www.sap.com/products/sustainability-control-tower.html | - || – | Sphera SCS (formerly SupplyShift) | Supply Chain Sustainability (SCS) | - | - | https://sphera.com/solutions/supply-chain-transparency/supply-chain-sustainability-solution/standard-assessments/ | - || – | Sweep | Carbon Management Platform | - | - | No public software level assurance statement found (as of 2025-10-12) | - || – | Workiva (Sustain.Life) | Carbon / ESG Platform | - | - | No public software level assurance statement found (as of 2025-10-12) | - |## Transferable questions for any vendor1. Scope: Does the statement explicitly cover the methodology or calc engine?2. Level: Limited or reasonable? Any exclusions?3. Versioning: Which release is covered, and how are updates handled?4. Verifier: Who did the work, and are they accredited/recognized?## What this means for buyersUse the league table during shortlisting and RFPs. Require links to assurance statements and keep copies with your audit evidence. When a vendor updates factors or logic, request updated assurance scope notes or a fresh statement.---