TGO’s 2 November Grid Factor Rule Can Give One Company Two Numbers for the Same Base Year

On 2 November 2026 the Thailand Greenhouse Gas Management Organization (TGO) published a one-page notice that takes effect the same day. It tells organisations which grid electricity factor to use for Scope 2, depending on the year of the data. It also treats two kinds of base year differently: a Carbon Footprint for Organization (CFO) base year can stay as certified, while a certified Net Zero base year from 2022 onward has to be recalculated.

It is a short notice, but it reaches the numbers listed companies publish. Any company using one base year for both purposes should read it before its FY2026 inventory closes.

What TGO issued on 2 November

TGO published the 0.4750 factor on 26 November 2025. Its CFO emission factor file makes the factor mandatory from 1 January 2026, based on the 2022–2024 grid mix, and notes that the older 0.4999 factor, based on the 2016–2018 mix, could be used until 31 March 2026. What was missing was an instruction on history. The 2 November notice, issued by TGO’s Low Carbon Business Certification Office, now provides one.

How one company ends up with two numbers

The two tracks are connected. TGO’s revised Net Zero criteria build the base year on data holding a TGO CFO mark. So take a company whose 2023 base year was certified while 0.4999 was still in use, and which has since entered the Net Zero track.

Under the notice, the CFO base year may stay where it is, and the Net Zero base year for the same 2023 data must move. Unless the company chooses to recalculate its CFO base year too, it now holds two valid Scope 2 figures for 2023. This is our reading of the notice, not a TGO statement, but it follows directly from the two instructions.

The Net Zero recalculation also has a consequence beyond the Scope 2 figure itself. The criteria measure the required cut of at least 90% against the base year (§5.4), and cap removal-credit offsets for the remainder at 10% of base-year emissions (§9.3.1). A lower base year therefore means fewer tonnes of permitted residual. In the example below, the cap on that Scope 2 portion falls by about 50 tonnes.

The 5% your Scope 2 chart may show without any action

The CFO relief has its own effect on reported trends. A company that keeps a base year from 2021 or earlier at 0.4999 and reports FY2026 at 0.4750 will show a Scope 2 reduction even if its electricity use has not changed at all.

This is not an error. The factor reflects a change in the national grid mix, and TGO has said the base year may stand. But it is not the result of anything the company did, and a reader of a sustainability report will assume otherwise unless told. The GHG Protocol Corporate Standard requires a company to set a base-year recalculation policy and state any significance threshold, and lists improved emission factors with a significant impact among the recalculation triggers. It does not define “significant”. Whether 5% on Scope 2 crosses your threshold is a judgement to make on purpose and document.

What the notice does not settle

The notice runs to one page, and several questions remain open. We would put these to TGO in writing, at the contact on its carbon label site, rather than assume an answer:

Why the English edition has to carry this

This notice is in Thai. TGO’s English download page links to the same Thai PDF, and we found no English version. The people who read your FY2026 English report will not see the distinction unless your report explains it.

That matters for three reasons we can document. FTSE Russell scores from public disclosure with no questionnaire. Its FAQ §1.8 recognises the importance of local languages, but Thai is not among the key languages it names, and SET’s Q&A 16 recommends English disclosure because FTSE assesses primarily from English. S&P Global’s language policy says it may machine-translate non-English evidence and takes no responsibility for translation errors. And CDP’s terms state a response in an unlisted language, which includes Thai, will not be scored.

Translating the term is the easy part: คำนวณปีฐานใหม่ is “base-year recalculation”. The harder part is carrying the whole method across, consistently, so the English report states:

This becomes more than a housekeeping point for SET50 companies. Their first mandatory ISSB reporting year is FY2027, with the first filing in 2028. The SEC’s One Report-S seminar deck makes the 2004 GHG Protocol the default and allows TGO’s method during the five-year relief. It describes the two as not materially different for Scope 1 and 2, but flags that a power buyer’s Scope 2 under the GHG Protocol excludes transmission losses. Ask your verifier how your factor treats that. The deck is not the final form, so check the form itself before relying on these details. Our work on IFRS S1 and S2 disclosure starts from that mapping.

Where the evidence runs out

We have no evidence that any rater has marked a company down over this factor, or that FTSE Russell’s methodology looks at base-year factor choices at all. We also found no count of how many companies hold a certified Net Zero base year from 2022 onward, so we cannot size the group affected. TGO’s verification protocol is on CDP’s accepted list, so a TGO-based number is not a weakness in itself, although CDP also asks for an accredited third-party provider. And for a company with little purchased electricity, 5% of Scope 2 may be immaterial. The case for acting is control over a number you publish, not a penalty we can point to.

What to do before the next TGO round

TGO’s published schedule gives the next round, 2/2570, a document deadline of 20 November 2026, a fee date of 24 November, meetings on 8 and 23 December, and results on the evening of 23 December. The round after that, 3/2570, takes documents by 25 January 2027. CFO certificates on the register, read on 6 November, run for one year, so most holders return to these questions at renewal. The register shows 1,425 records under valid licence, out of 4,624 issued, and 25 registered CFO verification bodies. Those are site-level certificate records rather than companies.

For how TGO data reaches rated disclosure, see TGO carbon to FTSE disclosure. Dates across the Thai calendar are in our ESG regulatory tracker.

Sources, read 6 November 2026: TGO, guidance on the electricity emission factor for CFO and Net Zero (2 Nov 2026); TGO CFO emission factor file (Feb 2569); TGO Net Zero criteria, revision 1 (Jul 2569); TGO round schedule and registers; GHG Protocol Corporate Standard, ch. 5; SEC Thailand, 56-1 One Report-S seminar deck (Oct 2026); FTSE Russell ESG Scores FAQ v1.5; SET Q&A sessions; S&P Global CSA Language Policy; CDP Terms of Disclosure and verification list. Worked figures are illustrative and our own. This article is general information, not advice on your inventory.