Scope 3 Carbon Software: Verification League Table (2025)

Scope 3

Alex Rudnicki

COO

4 min read

Table of contents

Howden manages Scope 3 PG&S emissions across 55 countries with DitchCarbon.

See what the platform could do for you.

Book a demo

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

Verified	Vendor	Product or module	Standard / level	Verifier	Evidence	Assurance date

Yes	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) & programme verification (June 10, 2025)	June 10, 2025
Yes	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	-
Yes	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	-
Yes	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	-
Yes	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	-
No	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	-
No	Carbon Interface	Emissions API	-	-	No public software level assurance statement found (as of 2025-10-12)	-
No	Climatiq	Emission factors & API	States 'scientifically vetted' emission factors; methodology hub	-	https://www.climatiq.io/methodology	-
No	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	-
No	Gravity Climate	Carbon & energy management platform	Positions as 'audit friendly'; customers pass audits	-	https://www.gravityclimate.com/blog/june-2025-product-updates	-
No	IBM (Envizi)	Envizi ESG Suite	-	-	https://www.ibm.com/products/envizi	-
No	IBM EIS GHG APIs	Environmental Intelligence Suite - GHG APIs	-	-	No public software level assurance statement found (as of 2025-10-12)	-
No	Manufacture 2030	M2030 Platform	-	-	No public software level assurance statement found (as of 2025-10-12)	-
No	Normative	Carbon Accounting Methodology	-	-	No public software level assurance statement found (as of 2025-10-12)	-
No	OpenCO2 (CO2API)	Emission Factors API	-	-	No public software level assurance statement found (as of 2025-10-12)	-
No	Plan A	Platform & Methodology	-	-	No public software level assurance statement found (as of 2025-10-12)	-
No	SAP	Sustainability Control Tower	-	-	https://www.sap.com/products/sustainability-control-tower.html	-
No	Sphera SCS (formerly SupplyShift)	Supply Chain Sustainability (SCS)	-	-	https://sphera.com/solutions/supply-chain-transparency/supply-chain-sustainability-solution/standard-assessments/	-
No	Sweep	Carbon Management Platform	-	-	No public software level assurance statement found (as of 2025-10-12)	-
No	Workiva (Sustain.Life)	Carbon / ESG Platform	-	-	No public software level assurance statement found (as of 2025-10-12)	-

Transferable Questions for Any Vendor

Scope: Does the statement explicitly cover the methodology or calc engine?
Level: Limited or reasonable? Any exclusions?
Versioning: Which release is covered, and how are updates handled?
Verifier: Who did the work, and are they accredited/recognised?

What This Means for Buyers

Use 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.

‍

See the coverage on your own category register

Send us your supplier list and we will show you the coverage and the data quality behind each figure, so you can see which of your significant categories can be upgraded off spend-based data.

Request a walkthrough

Claim your profile