UK SRS Scope 3: categories, data quality and financed emissions

What UK SRS S2 actually requires for Scope 3

The common misconception is that Scope 3 reporting means filling in all fifteen GHG Protocol categories.

It does not.

UK SRS S2 requires an entity to disclose its absolute gross Scope 3 greenhouse gas emissions where those emissions are material, and to state which of the fifteen categories in the GHG Protocol Corporate Value Chain (Scope 3) Standard are included in the measurement^[1].

Those fifteen categories come straight from the GHG Protocol Corporate Value Chain (Scope 3) Accounting and Reporting Standard, published in 2011, which UK SRS S2 references directly^[4].

Scope 3 is one part of the wider climate disclosure. For the full picture, see our UK SRS S2 climate disclosures analysis and the broader UK SRS requirements.

The 15 categories: upstream and downstream

The GHG Protocol splits Scope 3 into eight upstream categories — emissions linked to what an entity buys and operates — and seven downstream categories linked to what it sells^[4].

Category 15 (Investments) is where financed emissions sit, and it carries its own UK-specific treatment, covered below.

Materiality, not a complete census

UK SRS S2 frames the obligation around material categories: an entity discloses absolute gross Scope 3 emissions where material and states which categories are included^[1].

The standard does not prescribe a single quantitative threshold.

The judgement is one of materiality to users of general purpose financial reports, and it should be documented so that the basis for including or excluding a category can be understood and, in time, assured.

That documentation is also the foundation for any future FCA supervisory review and for the comply-or-explain mechanics described later on this page.

The data-quality hierarchy S2 requires

The part of UK SRS S2 most likely to catch reporters out is not the category list — it is the requirement to be explicit about how the numbers were produced.

The standard requires an entity to use a measurement approach, inputs and assumptions that result in a faithful representation of its Scope 3 emissions, and to use all reasonable and supportable information available without undue cost or effort^[1].

In practice that means prioritising direct measurement and primary data over estimation, and disclosing where activity- specific data has been used and where it has not^[1].

For UK-specific emission factors, the Department for Energy Security and Net Zero publishes government conversion factors for company reporting each year, supplemented by supplier-specific data where it exists^[6].

Financed emissions and the UK paragraph B59A addition

For financial institutions, Category 15 dominates. UK SRS S2 requires entities whose activities include asset management, commercial banking or insurance to disclose additional information about financed emissions as part of their Scope 3 disclosure^[1].

The UK made one targeted change here. On the Technical Advisory Committee’s recommendation, the government inserted paragraph B59A into UK SRS S2^[2].

B59A requires a financial institution that determines it is impracticable to reliably estimate financed emissions for the same reporting period as its financial statements to explain why it has not disclosed in line with paragraph B59 — including its measurement approach, such as use of the prior period balance sheet, and how it plans to meet the requirements in full^[2].

UK SRS S2 also incorporates the ISSB’s December 2025 amendments: it removes the mandatory use of the GICS classification and permits entities to exclude emissions associated with derivatives, facilitated emissions and insurance-associated emissions from Category 15, so they can report financed emissions as defined in the standard^[2].

Comply-or-explain and the one-year relief

Scope 3 is treated more leniently than Scope 1 and 2 in the FCA’s proposed listed-company rules.

Under CP26/5, in-scope listed companies in UK Listing Rules categories 6, 16 and 22 would report against UK SRS S2 for accounting periods beginning on or after 1 January 2027^[3].

Scope 3 emissions, however, move to a comply-or-explain basis for accounting periods beginning on or after 1 January 2028 — a one-year transitional relief that gives reporters extra time to build value-chain data^[3].

These remain FCA proposals. CP26/5 closed on 20 March 2026, and the FCA aims to publish a Policy Statement with final rules in autumn 2026^[3].

For the full set of dates from publication to mandatory reporting, see our UK SRS deadline tracker.

Assurance readiness

Assurance of Scope 3 is not mandatory under the FCA proposals, but building for it is sensible.

The FRC published the voluntary UK sustainability assurance standard, ISSA (UK) 5000, in November 2025, and the government is developing an oversight regime with the FRC establishing an interim regime^[5].

The practical implication is to keep an auditable trail now: methodology decisions, data sources, assumptions and quality controls for each material category.

Reporters must also state whether any voluntary third-party assurance was obtained.

Software that captures conversion factors, activity data and audit trails makes this far easier — see our carbon reporting software comparison.

UK SRS Scope 3: frequently asked questions