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Independent research directory · Informational only · No regulator affiliation
SB253 Vendors

Category

Assurance and verification vendors

Last reviewed: September 20, 2026

Organizations that state they offer verification or assurance services related to greenhouse gas information. Accreditation details, where shown, are as displayed on the cited source page on the date shown; confirm with the accrediting body and the provider.

Descriptions are short summaries of what each vendor or source states publicly. SB253 Vendors has not independently verified them. Listings are alphabetical and are not a ranking.

Vendors in this category

  • Apex Companies

    Firm whose sustainability page describes verification of GHG emissions and other sustainability metrics, citing ISO 14064-3, ISSA 5000 and AA1000AS.

  • Aster Global Environmental Solutions

    Firm offering third-party auditing, validation and verification of GHG inventories, including organizational-level verification, and states ANAB accreditation under ISO 14065.

  • BDO USA

    Accounting firm describing limited and reasonable sustainability assurance, readiness assessments, and GHG inventory support, and referencing SB 253 reporting.

  • Bureau Veritas

    Testing/inspection/certification group offering carbon footprint verification including organizational Scope 1-3 verification, referencing ISO 14064 and the GHG Protocol.

  • Cventure LLC

    Firm describing third-party GHG verification at project, facility, corporate, municipal and national levels for disclosure programs and registries.

  • Deloitte (US)

    Accounting and advisory firm whose US page describes sustainability assurance integrated with financial audit, plus GHG inventory and carbon assessment services.

  • DNV

    Assurance and certification group whose pages describe third-party verification of corporate carbon footprints and GHG emissions against ISO 14064-1 and the GHG Protocol.

  • ERM CVS

    Independent assurance and verification arm of ERM Group; its SB 253 page cites ISAE 3000, ISAE 3410 and ISO 14064-3 for GHG assurance and offers assurance-readiness assessments.

  • EY (US)

    Professional services firm whose US climate page lists assurance over data and disclosures and greenhouse gas and energy audits.

  • Intertek

    Assurance provider stating independent GHG validation and verification to ISO 14064-3, with ISAE 3000 and AA1000 engagement options for Scope 1, 2 and 3.

  • KPMG (US)

    Professional services firm whose US page describes limited or reasonable assurance over metrics including greenhouse gas emissions, and GRI and SASB reports.

  • LRQA

    Certification and assurance group offering ISO 14064 validation and verification of organizational carbon footprints, plus GHG inventory services.

  • PwC (US)

    Professional services firm whose US page describes independent ESG assurance, including over selected metrics such as GHG emissions.

  • RSM US

    Accounting and consulting firm whose US page lists ESG attestation, greenhouse gas assurance and agreed-upon procedures.

  • SCS Global Services

    Third-party GHG inventory verification body covering Scope 1, 2 and 3, with verification against GHG Protocol and several program rules.

  • SGS

    Inspection and certification group offering verification of GHG inventories to ISO 14064-1, at limited or reasonable assurance, with accredited and non-accredited options stated.

  • TUV SUD

    Testing and certification group offering GHG verification of corporate carbon footprints (ISO 14064-1, GHG Protocol) and projects, with verification following ISO 14064-3.

  • UL Solutions

    Testing and certification company offering GHG statement verification to ISO 14064-3 at limited or reasonable assurance for enterprise and product carbon footprints.