The GHG Protocol: the accounting standard behind UK SRS emissions

Developed by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD) 1, the GHG Protocol has become the authoritative framework for corporate carbon accounting globally 2. Every major climate reporting framework — from CDP and ISSB standards to the EU's CSRD — builds on its methodology 2.

UK SRS S2 mandates the GHG Protocol Corporate Standard as the required methodology for emissions measurement 4. This ensures UK climate disclosures align with international best practice and remain comparable across jurisdictions 4.

The GHG Protocol divides corporate emissions into three scopes, establishing the foundation for modern carbon accounting 1. This classification system ensures comprehensive coverage of a company's climate impact across its entire value chain 1.

Scope 1 covers direct emissions from sources a company owns or controls — fuel combustion in its boilers, vehicles and processes 1. Scope 2 covers indirect emissions from the electricity, steam, heat and cooling it purchases 1. Scope 3 covers all other indirect emissions across the value chain, upstream and downstream — and is usually the largest share of a company's footprint, often representing 70-90% of total emissions 3.

UK SRS S2 requires all three scopes, with Scope 3 reported by significant category 4. For the complete methodology across all 15 Scope 3 categories and step-by-step inventory building, see the dedicated Scope 3 guide on srsreport.co.uk.

Beyond the headline emissions numbers, UK SRS S2 requires companies to disclose the methodology behind their calculations 4. This includes the measurement approaches used, key inputs and assumptions, the extent to which Scope 3 calculations use activity-specific data rather than estimates, and the scope of independent verification 4.

The GHG Protocol provides the backbone for all UK SRS reporting — the standardized language that makes emissions disclosures comparable across companies, sectors, and international frameworks 1. Its three-scope structure, calculation methodologies, and reporting principles ensure consistency whether companies are reporting under UK SRS S2, TCFD requirements, or preparing for transition plan disclosures 2.

Because UK SRS S2 is built entirely on GHG Protocol foundations 4, the current major revisions will directly shape UK reporting practice over the coming years. Companies implementing UK SRS compliance systems now should build flexible measurement frameworks that can adapt to the updated standards arriving in 2027-2028 34.