The ISO 14064-1 GHG report: a section-by-section preparation guide

What sections make up an ISO 14064-1 report?

The table below sets out the sections of a typical inventory report that meets the standard's reporting requirements. The second column is what belongs in the section; the third is what a verifier actually looks for there. Writing each section with the third column in mind is the single cheapest way to reduce findings.

Alongside these nine sections, the report also carries data quality management, biogenic emissions, exclusions, definitions, abbreviations and references. None of these is filler: the verifier cross-checks the exclusions list against the materiality section, traces factor sources through the reference list, and builds the sampling plan from the data quality section.

How do ISO 14064-1 categories map to Scope 1, 2 and 3?

This is where most inventories get muddled. ISO 14064-1:2018 does not say Scope 1, 2 or 3. It distinguishes direct emissions, indirect emissions from imported energy, and other indirect emissions — splitting the indirect side into four categories. The GHG Protocol Corporate Standard uses Scope 1, Scope 2 and a fifteen-category Scope 3. The two do not conflict; they shelve the same emissions differently.

Three classic mistakes

• Putting your own fleet in category 3. Fuel burned in vehicles you own or operationally control is a direct emission — category 1. Category 3 covers transport you do not control.
• Assuming a Scope 3 category maps one-to-one. In the GHG Protocol a purchased good and its inbound freight both sit in Scope 3; under ISO the good goes to category 4 and the freight to category 3. Build the mapping at source level, not category level.
• Believing ISO mandates every indirect emission. What is mandatory is a documented significance criterion explaining which indirect emissions you include and why, together with a justification for what you leave out.

Should Scope 2 be location-based or market-based?

Both. The GHG Protocol Scope 2 Guidance requires dual reporting: the location-based figure uses the average grid intensity (a national factor or IEA data), while the market-based figure reflects contractual instruments — REGOs, guarantees of origin, I-RECs, supplier-specific factors or the residual mix.

Report a single number and the verifier's first question is which one it is. If your reduction claim rests on certificates, expect to produce serial numbers, cancellation (retirement) records and evidence that they match the consumption period. A zero-emission claim cannot be defended on certificates that were never cancelled.

Which emission factors should you use, and why does the vintage matter?

Factor selection is not a technical preference; it is a decision that has to be documented. There are four main sources, and your methodology section must state which you chose and why.

Findings rarely come from arithmetic. They come from an unrecorded answer to a simple question: which factor, which version, and why.

Why are uncertainty and materiality required, and how do you handle them?

The point of an uncertainty assessment is not to produce a precise error bar; it is to make clear how much weight each number can carry. Treat the two components separately: activity data uncertainty (meter accuracy, estimated invoices, unit conversion, gap-filling) and emission factor uncertainty (how well a default factor represents your process).

A qualitative rating per source, weighted by that source's share of the inventory, is the right middle ground for most organisations. The step that matters is the next one: a concrete improvement plan for sources that are both high-uncertainty and high-share. Those are exactly the sources a verifier puts at the top of the sampling list.

Materiality connects directly to the verifier's own judgement: they aggregate the uncorrected misstatements they find and compare the total against a threshold before wording their statement. A threshold around 5% of total emissions is common in practice, but it varies with the assurance level and the verifier's own procedure — confirm it before you sign. Define your own threshold on the same logic and show, with an estimate, that everything you excluded stays below it. An exclusion whose magnitude was never estimated does not count as justified.

What will the verifier actually ask for?

Verification is not a document-reading exercise; it is a trace. The verifier picks a number in your report and walks backwards to its origin: total, category, source, individual record, evidence. Every broken link on that path becomes a finding — a CAR (corrective action request) or a CL (clarification request). The list below covers where first-time teams most often come unstuck.

1. 1

   Keep the traceability chain unbroken

   Every total in the report must trace to a category, the category to a source, the source to individual activity data, and that data to a piece of evidence. One manually overwritten cell and the chain breaks there.

2. 2

   Match evidence to the period

   Electricity and gas invoices, meter readings, fuel and fleet reports, delivery notes, refrigerant top-up records, waste transfer notes, renewable certificate cancellation statements. Thirteen invoices or a missing month gets asked about every time.

3. 3

   Write down your cut-off rule

   Where billing periods straddle the reporting year, the pro-rata rule must be documented and applied identically each year. A cut-off rule that shifts between years undermines any reduction claim on its own.

4. 4

   Keep the calculation reproducible

   A verifier should be able to pick any source at random and redo it by hand: activity data, unit, factor value, factor source and vintage, GWP and result all visible on one line.

5. 5

   Record factor versions

   Which factor was applied to which record, in which version, on which date. If the factor set was updated mid-year, it must be visible which records were recalculated.

6. 6

   Flag estimated data rather than hiding it

   Records based on estimation or extrapolation should be tagged, the method documented, and the estimated share of the total disclosed in the report.

7. 7

   Separate the roles

   Whoever enters the data, whoever checks it and whoever approves it should be different people, with approval records stamped by user and date. A one-person process reads as an absence of internal control.

8. 8

   Lock the version and prove integrity

   You must be able to show the report has not changed since approval: version number, lock date, file hash and a trusted timestamp. The version the verifier reviewed and the version you published must be the same file.

9. 9

   Have last year's findings ready

   Prior-period CARs (corrective action requests) and CLs (clarification requests), together with evidence that each was closed, are among the first documents requested at the opening meeting.

10. 10

    Plan the site visit

    Facility list, meter locations for sampling, calibration records for measurement equipment and the availability of the relevant process owners should all be arranged in advance.

The most common findings repeat with remarkable consistency: an unstated factor source or vintage, a market-based Scope 2 claim without cancellation evidence, exclusions justified without an estimate of their size, broken spreadsheet formulas, and a number in the report that does not match the number in the database. All five are preventable by process design; none of them can be fixed during audit week.

What are the regulatory hooks in Türkiye and the UK?

In the UK, quoted companies and large businesses report energy and emissions under SECR within the annual report, using an accepted methodology and disclosing the emission factors applied. SECR is a disclosure regime rather than a verification regime, but an ISO 14064-1 inventory built to the structure above satisfies its methodological expectations comfortably — and the DESNZ conversion factors described earlier are the default source it assumes.

In Türkiye, installations in scope report under the Regulation on Monitoring of Greenhouse Gas Emissions (Official Gazette, 17 May 2014, no. 29003; last amended 31 May 2017): the monitoring plan is submitted at least six months before activity begins, the annual verified emissions report is due by 30 April, and verification is performed by third parties accredited to ISO 14065 through TÜRKAK. Climate Law no. 7552 (Official Gazette, 9 July 2025, no. 32951) established the legal framework for a national emissions trading system, with installations given until roughly July 2028 to obtain a greenhouse gas emissions permit. If you have Turkish operations in a CBAM sector, the same inventory data set feeds all three.

Where does CarbonTrex fit — and where does it not?

To be clear: CarbonTrex is not a certification or verification body. It does not issue ISO 14064-1 certificates or verification statements — that work belongs to accredited bodies. What CarbonTrex does is produce the inventory and the report in the form a verifier will ask for.

• —ISO 14064-1 compliant nine-section PDF report generation
• —12,000+ emission factors: IPCC EFDB, the multi-year DEFRA set, IEA grid factors and organisation-specific factors
• —Factor change history — which version was applied to which record
• —Source-level uncertainty analysis and materiality assessment
• —Base year management and year-on-year comparison
• —Evidence document upload and an Excel audit trail
• —RFC 3161 timestamping and report hashing for version integrity
• —A read-only portal dedicated to your verifier

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