Microsoft’s Chief Sustainability Officer, Melanie Nakagawa, emphasized on LinkedIn earlier in May 2025 that reaching their 2030 carbon negative goal hinges on more than ambition—it demands accountability, agility, and collaboration.

With the Microsoft Climate Council driving progress, the focus is now on three critical levers: efficiency, availability, and measurement and adoption—all essential to accelerating impact and empowering suppliers to act with urgency.

This is not just a corporate priority—it’s a shared responsibility. As Microsoft deepens its climate commitments, suppliers are expected to match that urgency with credible, transparent emissions data. The 2025 Disclosure Cycle is a pivotal moment to demonstrate climate leadership, meet compliance expectations, and strengthen long-term partnerships with Microsoft.

• Deadline-driven: Applies to 2019 baseline and 2024 emissions.
• Mandatory assurance or consultant validation required.
• Scope 1, 2, and 3 (Categories 1–8) must be reported— even if zero or immaterial.
• SLA emissions must be broken down by service, volume, and UNSPSC code.

Microsoft’s Supplier Code of Conduct (Section 6.11) mandates that suppliers obtain independent third-party assurance—or engage with an external consultant—on their greenhouse gas (GHG) emissions data to ensure its accuracy and completeness.

This requirement applies to both the 2019 baseline emissions (or an approved alternative year) and the 2024 annual emissions. Either approach enhances the credibility of the disclosed emissions and supports Microsoft’s commitment to transparent and reliable climate reporting.

To boost the credibility of supplier-reported emissions, Microsoft is implementing enhanced data integrity requirements for the 2025 Disclosure Cycle. These apply to both total company emissions and Service-level Accounting (SLA) emissions for the 2019 baseline (or approved alternative) and 2024 reporting year.

Suppliers must select one of two verification options—either an Assurance Letter from an independent third party or a Consultant Letter from a qualified external advisor—for each emissions category. Microsoft allows flexibility to combine methods (e.g., Assurance for Scope 1 & 2, Consultant for Scope 3) to meet compliance effectively.

Before diving into how CEMAsys can support you, it’s important to recognize that ESG reporting is complex—there are multiple frameworks, each with its own standards and expectations. Understanding these frameworks is essential for ensuring full compliance with evolving regulatory and corporate requirements.

That’s where CEMAsys comes in. With a powerful ESG platform and expert advisory services, CEMAsys helps Microsoft suppliers navigate this complexity and meet every emissions disclosure requirement with confidence.

Learn more about ESG reporting frameworks here:
ESG reporting requirements | Cemasys

We help with both verification pathways available for Microsoft Supplier Disclosures

• We are an independent third-party assurance provider accredited with CDP and SBTi.
• Ensures compliance with standards like AICPA, PCAOB, IAASB.
• Supports limited assurance engagements as required by Microsoft.

• CEMAsys consultants help calculate and document emissions.
• Provides a compliant Consultant Letter on official letterhead.
• Includes all required scopes, SLA breakdowns, and calculation methodologies.

• Emissions data for Scope 1, 2, and 3 (Categories 1–8)
• Reporting periods: 2019 baseline and 2024
• Methodology used (e.g., GHG Protocol)
• SLA-specific data: service breakdown, reference units, UNSPSC codes
• Format: English, PDF, 1–3 pages

The clock is ticking. Microsoft’s expectations are clear, and the consequences of non-compliance are real. CEMAsys is uniquely positioned to help you:

• Streamline data collection
• Ensure reporting accuracy
• Meet Microsoft’s assurance or consultant requirements
• Strengthen your position as a trusted supplier