17 April 2026
GHG Protocol Scope 3 Rules Are Changing: What ASRS Reporters Need to Know
The GHG Protocol is proposing its most significant update to the Scope 3 standard since 2011. Here's what it means for ASRS reporters and how to prepare.
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Why this matters for ASRS reporters
The GHG Protocol and AASB S2 are not separate systems, one depends directly on the other. That is not incidental. It means that when the GHG Protocol updates its Scope 3 standard, ASRS reporters do not get to decide whether the changes apply to them.
Any revisions to methodology, coverage requirements, or category definitions flow directly through to what a conformant AASB S2 disclosure looks like.
For businesses building Scope 3 processes right now, understanding the direction the standard is heading is as important as knowing what the current standard says.
What’s actually changing
The GHG Protocol is proposing the most significant update to its Scope 3 standard since 2011. The proposed revisions are still pre-consultation draft, but they signal where the standard is going clearly enough to act on.
The accountant’s instinct here (to want complete, documented, and verified numbers) is exactly what the updated standard is moving toward.
Treating Scope 3 like a financial accounting problem, not a sustainability project, is how businesses will end up with inventories that hold up to audit scrutiny.
A 95% coverage threshold
This is the most consequential proposal.
Under the current standard, companies must justify any Scope 3 category exclusions, but there is no defined minimum.
The proposed revision would require at least 95% of required Scope 3 emissions to be reported for an inventory to be conformant. The remaining 5% is the ceiling for exclusions, not the starting point.
For companies who have historically taken a narrow view of their material Scope 3 categories, this is a direct challenge to the status quo.
The shift is from “disclose what you excluded and why” to “prove you’ve covered 95% of it.”
A narrower, clearer Category 15
Currently Category 15 (Investments) is widely misread as applying only to investment managers.
The proposed standard would make explicit that it applies to all companies. At the same time, insurance-associated emissions, underwriting, and issuance activities would shift out of Category 15 and into optional Category 16 subcategories.
For financial services clients, this reclassification has direct practical implications for how their Scope 3 inventory is structured.
A new Category 16 for facilitated emissions
The current 15-category structure has been unchanged since 2011.
The proposed revisions would add Category 16 to capture value chain activities that don’t fit elsewhere, including facilitated emissions, licensing arrangements, and certain financial services activities currently sitting within Category 15.
Most Category 16 reporting would be optional, but its introduction reflects the standard’s intent to close off the exclusions that have accumulated in the edges of the current framework.
Mandatory data quality disaggregation
Companies would be required to break down their reported Scope 3 emissions by data type for each category (distinguishing between primary data, supplier-specific calculations, and spend-based or activity-based estimates).
A separate proposal would require disclosure of verification status: verified, partially verified, or not verified.
Together, these two requirements make methodological choices visible in a way they currently aren’t. An inventory built on spend-based estimates will look different sitting beside one built on supplier-specific data, which creates both a transparency incentive and, over time, a genuine competitive reason for businesses to improve data quality.
What the timeline looks like
The revised standard is not imminent, but the preparation window is shorter than it appears.
- March 2026 progress update published (out now)
- Full public consultation draft (later in 2026)
- Revised standard finalised (Expected 2027)
- New standards eligible for use (2028 or later)
Three practical steps worth taking now
Audit Scope 3 coverage
Map your current inventory against all 15 required categories. Which ones are being measured, which excluded, and on what basis? If the current approach would fail a 95% completeness test, it’s better to know that now than when the new standard is in effect. This is a useful exercise regardless of the GHG Protocol revision.
Classify data quality by category
Know where your Scope 3 numbers are coming from (spend-based estimates, activity-based calculations, or supplier-specific data). The data disaggregation requirement is coming, and the groundwork for it is good accounting practice anyway. Businesses who can already distinguish data tiers by category will be ahead when the disclosure is mandatory.
Review Category 15 for any business that is in financial services
If you are an insurer, lender, or investment manager who has not been counting financed emissions, the proposed changes close off the “that doesn’t apply to us” position. Getting ahead of that conversation now is more useful than raising it when the updated standard drops.
Disclaimer
This post is based on GHG Protocol’s March 2026 Scope 3 Standard progress update. The document is pre-consultation draft material and subject to change.
Check Standards Development and Governance Repository | GHG Protocol for the latest version before making compliance decisions.