GHG reporting software: what the standard asks of it

The Scope 2 Guidance of January 2015 amended the Corporate Standard, so its requirements are the standard’s requirements.

Companies with any operations in markets providing product or supplier-specific data in the form of contractual instruments shall report Scope 2 in two ways and label each result: one location-based, one market-based.

The second half is rarely quoted: where a company only operates in markets without such data, only one Scope 2 result is reported, based on the location-based method.

The location-based method reflects the average emissions intensity of the grids where consumption occurs; in the UK that is the DESNZ grid factor.

The market-based method derives factors from contractual instruments — what the company purposefully chose, or its lack of choice — and it is not a renewables method, since fossil and mixed-supply instruments count too.

The two totals are not gross and net, and the Guidance says so.

UK SRS S2 paragraph 29(a)(v) requires the location-based figure and information about any contractual instruments needed to understand it; it does not require dual reporting.

Contractual instruments must meet eight quality criteria, which GHG Protocol’s own revision framework reproduces from Table 7.1 of the Guidance.

Criterion 3 turns a procurement fact into a software fact: instruments must be tracked and redeemed, retired or cancelled by or on behalf of the reporting entity.

In the UK the instrument is the REGO, issued through Ofgem’s register, and it conveys an attribute claim, not an emissions reduction, so it is not an offset.

A certificate bought but not retired is evidence of nothing, and a platform that lets you enter “100% renewable” as a percentage cannot demonstrate criterion 3 to an assurer.

Criterion 8 requires a residual mix for whatever electricity you did not claim with instruments, or a disclosure that none is available.

The Association of Issuing Bodies publishes a Great Britain residual mix — 280.64 gCO2 per kWh for 2025, on an untracked share of 58.16% — but says official residual mixes are in principle published by national authorities, and no UK authority adopts it.

Ofgem runs fuel mix disclosure, a different instrument, and DESNZ publishes a fuel mix disclosure data table; the conversion factors contain no residual mix at all.

So the disclosure limb of criterion 8 is live for most UK reporters, and the question for a vendor is what the platform prints when no residual mix is available: a silent substitution is an accounting choice made on your behalf.

The current set is Greenhouse gas reporting: conversion factors 2026, published by DESNZ on 11 June 2026, with a flat file for automatic processing corrected on 31 July 2026.

Its methodology paper states the rule that matters most: the 2026 factors are for use with activity data that falls entirely or mostly within 2026, so the factor year follows the activity year, not the filing year.

The UK electricity factor fell 26% from the 2025 set, and the major changes report attributes most of the fall to grid decarbonisation, with the remaining 6 to 7 percentage points due to methodological changes, improvements and corrections.

The method now uses data one year behind publication rather than two, so the 2025 set used 2023 data and the 2026 set uses 2025 data, and the series has no 2024 data year.

Part of any company’s Scope 2 fall between those years therefore comes from the factor, not from anything it did, and a year-on-year comparison spanning them should say so.

The methodology paper’s Table 9 prints the consumed factor, generated plus grid losses, as 0.14396; adding the two rounded workbook factors gives 0.14395, which is the same figure rounded differently, not a disagreement.

The paper tells users to report the generated factor as Scope 2 and transmission and distribution losses in Scope 3, which matches the GHG Protocol; putting the consumed factor in Scope 2 double-counts the losses if they are also reported in Scope 3.

There is no condensed set in 2026: DESNZ publishes the full set and the flat file, alongside a 152-page methodology paper and an 18-page major changes report.

Factors are updated annually, and DESNZ says they are regularly published in the first half of June; the collection page shows every edition, and the 2024 set is an example of one published later in the year.

A tool that stores a tonnage without the factor table, edition and basis cannot tell a change in what the factor measures from a change in what your company emitted.

Ask to see the factor version stamped on a specific figure from two years ago; if the answer is a settings page rather than a field on the record, the tool stores the answer and not the working.

GHG Protocol’s own technical assistance adds that Scope 2 factors should correspond to the relevant year, because a newer factor is not always a more accurate one for an earlier year.

Restatement is the least glamorous thing a GHG platform does and the thing that decides whether its output is worth anything after year three.

GHG Protocol’s 2019 Scope 1 and 2 guidance names three triggers: significant changes in the structure of the company, significant changes in the calculation methodology, and discovery of significant errors or smaller errors that are collectively significant.

It adds that the Corporate Standard does not have a set definition for “significant” and that a company should determine its own threshold, giving 2 percent as an example.

The 5% figure in circulation belongs to target setting: GHG Protocol’s own technical assistance notes that SBTi requires a significance threshold of 5% or less for recalculating target emissions.

What the standard requires is that you set your own threshold and disclose it, because Chapter 9 lists the base-year recalculation policy among the required reporting elements.

Structural changes — acquisitions and divestitures, outsourcing and insourcing, boundary changes, method changes and errors — make the base year and current year measure different things, so they trigger recalculation above the threshold.

Organic changes — a facility you built or shut, growth or decline in output, a genuine reduction — are what the trend line exists to show, and recalculating them away destroys the comparison.

An emission factor revision that changes what the factor measures, such as the 2026 grid factor’s new method, is a methodology change; one that reflects a genuinely different grid is not.

Chapter 9 requires appropriate context for any significant change that triggers recalculation, which is a documentation requirement your platform either supports or leaves to a file nobody can find in 2029.

The SECR obligations do not live in the 2018 Regulations: SI 2018/1155 is an amending instrument, and the operative requirements sit in Schedule 7 to SI 2008/410 — Part 7 for quoted companies and Part 7A for large unquoted companies and LLPs.

If a vendor cites the 2018 SI for a substantive requirement, it is citing the wrong document.

Paragraph 20D(6) lets a company leave out information it is not practical to obtain, but the report must state what is not included and why; neither that nor the offshore provisions is a licence to leave things out quietly.

A company that consumed 40,000 kWh or less in the United Kingdom need not give the figures, but paragraph 20D(7) requires the report to state that the information is not disclosed for that reason.

The test runs on all energy consumed, not only the gas, transport fuel and electricity the report covers, and the company stays in scope; a SECR module that prints nothing for a low-energy user has produced a non-compliant report.

SECR is not a Scope 3 regime: for unquoted companies the only value-chain element is transport fuel the company pays for, which the government guidance says includes fuel reimbursed on business mileage claims, and quoted companies have no transport-fuel Scope 3 limb at all.

The government guidance, the Environmental Reporting Guidelines, was last updated on 29 March 2019, through the 2025 size uplift, the publication of UK SRS and a factor edition in which the grid factor fell by a quarter.

Anything a platform calls SECR best practice after 2019 is the vendor’s view, not the government’s, and the guidance’s cross-reference to the Companies Act for the LLP threshold is out of date: the figures beside it are the right ones.

If SECR is your whole obligation, SECR requirements is the fuller treatment and the SECR reporting guide walks the disclosure.

ISAE 3410, Assurance Engagements on Greenhouse Gas Statements, is the IAASB’s standard written specifically for a greenhouse gas statement, and its withdrawal takes effect from the effective date of ISSA 5000: periods beginning on or after 15 December 2026.

What replaces it is general: ISSA 5000 applies to assurance engagements on sustainability information however presented, and the FRC issued ISSA (UK) 5000, as its November 2025 announcement explains, for voluntary use.

No UK regime requires assurance of a greenhouse gas figure; a listed company states whether it obtained assurance and, if so, the provider, the disclosures covered and the standards used.

The government’s assurance consultation led to a voluntary oversight regime, with the FRC tasked to establish an interim register by mid-2026; the FRC’s 2026/27 plan lists it as a deliverable, and no announcement that the register is open had been found as at 30 September 2026.

ISO 14064-1 is the preparer’s specification for organisation-level quantification and ISO 14064-3 the specification for verification; neither is an alternative to the GHG Protocol, and ISO describes the series as programme neutral, with a programme’s requirements additional to its own.

Strip away the standard-setting and the software requirement is the transparency principle again: an assurer will walk a number backwards, from the disclosure to the calculation, the factor and its version, the activity data, the source document, and whoever entered or changed it and when.

A platform that produces that chain on demand makes assurance a sampling exercise; one that cannot makes it a reconstruction project, billed by the hour — and sustainability assurance covers what an engagement involves.

Vendor demos are optimised: they show the chart at the end, on data prepared for the purpose.

These questions are built to be asked on the vendor’s own sample data, and each has an answer you can see on a screen rather than take on trust.

Each traces to a paragraph of a published document; none can be answered with a dashboard.

The tenth is for the people rather than the product: SECR paragraph 20F requires the directors’ report to state the methodologies used, which is a statement by directors, informed by a tool.

A vendor that cannot show factor versioning on a stored figure has told you something no comparison table can.