Published directory
Browse companies and consultancies by name or by the work they describe. Each profile links to the sources used for its published facts.
Last reviewed: September 20, 2026
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.
Showing 51 of 51 vendors
Carbon accounting software paired with optional expert services and sustainability certifications, aimed at small and mid-sized businesses.
Sustainability consultancy offering GHG inventory development, Scope 1/2 measurement and Scope 3 screening, with its own inventory software and California regulation pages.
Firm whose sustainability page describes verification of GHG emissions and other sustainability metrics, citing ISO 14064-3, ISSA 5000 and AA1000AS.
Firm offering third-party auditing, validation and verification of GHG inventories, including organizational-level verification, and states ANAB accreditation under ISO 14065.
Accounting firm describing limited and reasonable sustainability assurance, readiness assessments, and GHG inventory support, and referencing SB 253 reporting.
EHS and sustainability software including Scope 1-3 GHG tracking, air emissions modules, disclosure management and CSRD-oriented reporting.
BSI's consulting page describes GHG accounting and reporting support (Scope 1-3 inventories, verification preparation); BSI's separate pages also list ISO 14064-1 verification.
Testing/inspection/certification group offering carbon footprint verification including organizational Scope 1-3 verification, referencing ISO 14064 and the GHG Protocol.
AI-based carbon accounting platform for tracking Scope 1-3 emissions with automated data collection, supplier mapping and report templates.
Organization whose footprinting and reporting page describes helping corporates, cities and financial institutions measure Scope 1, 2 and 3 emissions against recognized standards.
Environmental data platform for apparel, textile and footwear brands, offering GHG inventories, product LCAs and framework reports.
Provider of an emission-factor database and API, plus tools for managing emission factors and calculating product carbon footprints.
EHS and sustainability software offering GHG emissions tracking across Scope 1-3, ESG targets and KPIs, and reporting to global frameworks.
Accounting and advisory firm whose US page describes GHG emissions accounting help across Scopes 1-3, based on the GHG Protocol, including readiness reviews of existing inventories.
Firm describing third-party GHG verification at project, facility, corporate, municipal and national levels for disclosure programs and registries.
Accounting and advisory firm whose US page describes sustainability assurance integrated with financial audit, plus GHG inventory and carbon assessment services.
Diligent's ESG product with a carbon calculator covering Scope 1-3, stakeholder data collection for Scope 3 and multi-report data reuse.
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.
Environmental database organization providing life cycle inventory datasets, API access, and climate-indicator and GHG-breakdown packages.
Sustainability consultancy whose pages describe sustainability reporting and disclosure support and GHG accounting work, including a private-equity GHG standard using the GHG Protocol.
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.
Professional services firm whose US climate page lists assurance over data and disclosures and greenhouse gas and energy audits.
Supply chain decarbonization platform combining supplier engagement, Scope 1-3 carbon accounting and renewable energy procurement; absorbed the Emitwise and Optera platforms.
IBM's ESG data and emissions software covering Scope 1-3 GHG accounting, financed emissions, decarbonization and ESG reporting.
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.
Environmental consultancy offering GHG assessments and inventories (Scopes 1-3), verification services, and SB 253 and New York reporting assistance.
Professional services firm whose US page describes limited or reasonable assurance over metrics including greenhouse gas emissions, and GRI and SASB reports.
Certification and assurance group offering ISO 14064 validation and verification of organizational carbon footprints, plus GHG inventory services.
Microsoft product for recording, calculating and reporting emissions, water and waste data, with Scope 1-3 calculations and dashboards.
Sustainability management software for ESG data collection, carbon emissions measurement, peer benchmarking and multi-framework disclosure reporting.
Software for carbon accounting and sustainability management covering Scope 1-3 measurement, reporting, decarbonization planning and financed emissions.
Carbon accounting and decarbonisation software for measuring, reporting and reducing corporate emissions, with AI features.
Sustainability and carbon management platform that centralizes ESG data, calculates Scope 1-3 emissions and prepares disclosures, for corporates and private capital firms.
Professional services firm whose US page describes independent ESG assurance, including over selected metrics such as GHG emissions.
Engineering and consulting firm whose insight article says it can support Scope 1 and 2 inventories; other pages describe climate calculations and decarbonization consulting.
Accounting and consulting firm whose US page lists ESG attestation, greenhouse gas assurance and agreed-upon procedures.
Salesforce ESG product for tracking Scope 1-3 emissions, forecasting toward net zero goals, and building framework-specific sustainability reports.
SAP's ERP-connected sustainability portfolio covering carbon accounting through a green ledger, footprint management and ESG steering and reporting.
Third-party GHG inventory verification body covering Scope 1, 2 and 3, with verification against GHG Protocol and several program rules.
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.
Climate consultancy whose GHG accounting page describes inventory support (notably Scope 3), data-gap work and help with disclosure frameworks.
Risk, safety and sustainability software provider whose offerings include GHG emissions management, Scope 3 tracking, sustainability reporting software and life-cycle-assessment data.
Platform for centralizing carbon and ESG data across a business and its value chain, with supplier data collection and multi-framework reporting templates.
Software for measuring and reducing corporate and product carbon footprints, with AI-assisted data ingestion, gap filling and reporting.
Environmental consultancy offering GHG inventories across all three scopes, GHG and CDP reporting support, and staff for SB 253 emissions reporting questions.
Testing and certification group offering GHG verification of corporate carbon footprints (ISO 14064-1, GHG Protocol) and projects, with verification following ISO 14064-3.
Testing and certification company offering GHG statement verification to ISO 14064-3 at limited or reasonable assurance for enterprise and product carbon footprints.
Enterprise sustainability platform for measuring emissions, drafting sustainability reports and planning reductions, with AI-assisted data tools.
Wolters Kluwer software for EHS, risk and ESG that includes a GHG management module for Scope 1-3 reporting and sustainability disclosure.
Reporting and disclosure platform whose sustainability offerings include Workiva Carbon for GHG accounting, plus ESG reporting, double materiality and data collection.
Engineering and consulting firm whose US page lists GHG inventory management and inventory verification aligned with ISO 14064 and AA1000, plus disclosure support.