An SECR disclosure can occupy a fairly small part of the annual report. I care much more about what sits behind it: which companies are included, where the energy and travel figures came from, and whether somebody can reproduce the calculation next year.
For unquoted companies and LLPs, the SECR thresholds remain more than 250 employees, turnover above £36 million and a balance sheet total above £18 million. Meet at least two of the three tests and you may be in scope.
Do not assume a new company-size label has taken you out of SECR. The general Companies Act thresholds rose in April 2025; the SECR thresholds did not.
I also don’t think “Scope 3 is voluntary under SECR” is a safe way to explain the rules. Full Scope 3 reporting is not required, but large unquoted companies and LLPs must include certain business travel in rental cars and employee-owned vehicles where the organisation buys or reimburses the fuel.
Those are the rules. The more interesting question is whether the number you eventually put into the accounts is one you can defend.
Who has to report under SECR?
SECR applies to quoted companies and to qualifying UK-incorporated unquoted companies and LLPs.
For an unquoted company or LLP, check whether you meet at least two of these three tests:
- more than 250 employees;
- turnover above £36 million;
- a balance sheet total above £18 million.
There is also a low-energy exemption. If the organisation uses 40 MWh or less of relevant energy during the reporting period, it may be able to omit the detailed energy and carbon figures. The annual report still needs to say that the exemption is being used.
The April 2025 company-size changes have made this less intuitive than it used to be. A business may now be medium-sized for some accounting purposes and still meet the SECR tests. If your classification changed, check SECR separately.
Groups deserve more attention than a simple threshold calculator can give them. The Government’s own 2026 review found continuing uncertainty around eligibility, site inclusion and group reporting boundaries. That does not surprise me. If the annual report consolidates several businesses, the carbon data needs to follow the reporting boundary rather than whichever collection of sites happens to be easiest to measure.
The same review estimates that 14% to 23% of organisations in scope may not be complying, and 19% of in-scope survey respondents did not recognise SECR by name. This is not a regulation that every qualifying business has quietly mastered.
What must an SECR disclosure include?
The minimum requirements differ between quoted companies and large unquoted companies or LLPs.
| Requirement | Large unquoted companies and LLPs | Quoted companies |
|---|---|---|
| Energy boundary | Relevant UK energy use | Global energy use, with the UK proportion identified |
| Scope 1 | Relevant UK emissions | Global Scope 1 |
| Scope 2 | Relevant UK emissions | Global Scope 2 |
| Scope 3 | Certain business travel is mandatory; other Scope 3 is voluntary | Voluntary under the minimum requirement |
| Energy | kWh | |
| Emissions | tCO2e | |
| Intensity ratio | At least one | |
| Method | State how the figures were calculated | |
| Previous year | Comparative figures after the first year | |
| Energy efficiency | Describe the principal measures taken | |
For a large unquoted company or LLP, the underlying energy data will normally include electricity, gas and relevant transport fuel.
There is no prescribed Government proforma. I would not spend much time worrying about whether your table looks like somebody else’s. Make it readable, certainly, but spend your effort on the figures behind it.
The Government’s 2026 evaluation estimates that SECR compliance takes an average of 94 hours of internal staff time a year, with a mean ongoing cost of about £7,100 per compliant organisation once external costs are included. The difficult work is not choosing a shade of grey for the annual-report table. It is getting usable information out of finance, facilities, fleet and travel systems and making the boundaries agree.
The first thing I look at is the reporting boundary
Suppose the accounts cover a parent and two subsidiaries. The electricity file covers all three, the gas file covers the parent and one subsidiary, and the mileage data are held separately by each finance team.
I would stop there before doing anything clever with emission factors.
The calculation first needs to describe the same organisation as the accounts. Acquisitions, disposals, leased sites and changes to the group during the year all deserve a look.
The Government’s 2026 review reaches much the same conclusion from a different direction. It identifies eligibility, site inclusion and group boundaries as persistent sources of confusion, particularly for private companies and LLPs.
Once the boundary is clear, the data work becomes much less mysterious. You are looking for electricity and gas consumption, relevant fuels, mileage or fuel records for the mandatory travel element, last year’s figures and enough information to explain material changes.
It will rarely arrive in one pristine file. One site may be missing two months. A subsidiary may have been sold in June. Mileage claims may record distance but not fuel type. Last year’s carbon number may survive in the annual report while the workings have disappeared.
That is the work I want to see exposed, because that is where confidence in the final figure comes from.
Do not mistake the SECR minimum for your company’s carbon footprint
This is the biggest conceptual mistake I would avoid.
For large unquoted companies and LLPs, SECR is deliberately limited. It does not require a complete value-chain footprint and its statutory coverage can be narrower than the footprint a business needs for management, reduction planning or other reporting frameworks.
The Government’s 2026 review actually warns about this. Organisations starting their carbon reporting journey from the SECR minimum can end up with an incomplete or UK-only baseline. Adding further emission sources or non-UK operations in later years can then make emissions appear to increase, even though the underlying business has not become more carbon intensive.
That can create an awkward conversation with a board that thought last year’s SECR figure was “the company footprint”.
Call the statutory disclosure what it is. If you also calculate the full organisational footprint, keep the difference clear.
Scope 3 is not simply voluntary
For quoted companies, Scope 3 is voluntary under the minimum SECR requirement.
For large unquoted companies and LLPs, there is a mandatory element covering business travel in rental cars and employee-owned vehicles where the organisation is responsible for buying the fuel. The guidance counts reimbursed business mileage within that, so a fuel claim an employee puts through expenses is inside the requirement.
That distinction is small in carbon-accounting terms and important in compliance terms.
The data are also easy to overlook because they often sit in expenses or mileage claims rather than in the files labelled “energy”. If your first SECR data request goes only to facilities, you may never see them.
Flights, rail travel, purchased goods, freight, waste and the rest of Scope 3 may still matter greatly to the organisation’s wider footprint. They are not all part of the minimum SECR disclosure.
A lower Scope 2 figure in 2026 may not mean you used less electricity
This is one of the first things I would check before congratulating a business on a large year-on-year fall.
The published UK electricity conversion factor is 0.17700 kgCO2e per kWh for 2025 and 0.13096 for 2026. That is a fall of about 26%.
Take a business using 100,000 kWh of electricity in both years:
- using the 2025 factor, that produces 17.7 tCO2e;
- using the 2026 factor, it produces 13.1 tCO2e.
Nothing has happened to the electricity consumption. The reported location-based Scope 2 figure has fallen by about 4.6 tonnes because the factor changed.
If the annual report says emissions fell because of efficiency measures, check the kWh before making that claim. The improvement may be partly, or even largely, the changing carbon intensity of the grid.
This is also why “we used the Government factors” is not enough for me. Record which year’s factor set you used.
There is a particularly current reason to do that. DESNZ republished the 2026 flat file used for automatic processing on 31 July 2026 after some unavailable values had initially been represented as zero. The full spreadsheet had been correct. The affected rows were not the core electricity and gas factors, but if your software imported the original automatic-processing file, update it rather than assuming every file labelled “2026” is identical.
What makes me trust an SECR number?
I want to be able to move backwards from the published figure.
If Scope 1 is 420 tonnes, where did it come from? Which gas bills, litres of fuel or vehicle records sit underneath it? If Scope 2 has fallen by 25%, did electricity consumption fall, did the organisational boundary change, or did the conversion factor move? If an estimate was necessary, can I see what was estimated and why?
I give much less weight to a polished methodology paragraph if the source trail underneath it has disappeared.
The Government framework recognises that some required information may genuinely not be practicable to obtain. In that case, you must state what has been omitted and explain why. Do not invent precision merely to fill a cell in the table.
For renewable electricity, I would also want to know which number I am looking at. The location-based grid-average figure is the mandatory one. Government guidance allows an organisation that buys renewable electricity under a power purchase agreement or through certificates to present a market-based figure as well. A green tariff is not a good reason to make the grid-average calculation vanish.
My SECR review checklist
Before the figures reach the annual report, these are the checks I think earn their keep.
1. Does the organisational boundary match the accounts?
Reconcile the entities, sites and reporting period first. If they do not match, stop and resolve it.
2. Is the organisation actually in scope?
Use the SECR thresholds rather than the newer general company-size label. If you are relying on the 40 MWh low-energy exemption, keep the evidence.
3. Can you trace the energy data?
Check the kWh, fuel and mileage back to bills, meter records, fuel records or expense data. Identify estimates and missing periods.
4. Have you included the mandatory business-travel element?
For large unquoted companies and LLPs, do not lose rental-car or employee-owned vehicle mileage simply because it sits outside the energy team.
5. Does the intensity ratio make sense for this business?
Turnover is common, but not automatically best. Employees, floor area or units produced can tell you more in some businesses. Choose a measure you can use consistently rather than the one that gives the prettiest result this year.
6. Can you explain the year-on-year movement?
Look at activity data, organisational changes and conversion-factor changes before attributing a fall to operational improvement.
7. Is the methodology specific enough to reproduce?
Record the factor year, boundary, material estimates, exclusions and any change from the previous methodology.
8. Does the energy-efficiency narrative describe things that actually happened?
If no principal measures were completed, say so. I would rather read that than see ordinary maintenance dressed up as a carbon programme.
What would make me send the calculation back?
A missing decimal place would not worry me nearly as much as any of these:
- the accounts and carbon calculation cover different organisations;
- a mandatory source has disappeared without explanation;
- nobody can identify which conversion-factor set was used;
- a large year-on-year change cannot be reconciled to activity, boundary or factor changes;
- the minimum SECR result is being presented as the company’s complete carbon footprint.
Those are not cosmetic problems. They change what the number means.
Is there an official SECR template?
No.
Government guidance provides an example format and encourages consistency, but there is no prescribed SECR proforma.
Be wary of anything marketed as the official SECR template. A template may save time; it does not confer compliance.
The Government’s 2026 review actually recommends considering standardised templates in future, because current disclosures vary so much in placement and formatting. That is evidence that one does not exist today.
Do you need independent assurance?
SECR does not create a separate requirement for independent assurance of the carbon calculation.
You may still need or want assurance because of another reporting framework, a board requirement, a lender or an auditor’s wider work on the annual report.
If you expect somebody else to review the calculation, make their life easier. Preserve the source data and workings rather than handing them a final tCO2e total and a methodology paragraph.
The 2026 SECR review: the parts I think matter
The Government recommends retaining SECR but amending it.
The obvious prospective changes are clearer rules on eligibility and group boundaries, better alignment with other frameworks, possible standardised templates and consideration of light-touch forward-looking elements.
What interested me more was the evidence underneath those recommendations.
The review estimates non-compliance at 14% to 23%. It found 19% of in-scope respondents did not recognise SECR by name. It also found that reporting has increasingly become a compliance exercise rather than something businesses use strategically.
That suggests the next version of SECR needs fewer ambiguities rather than more reporting theatre.
For now, though, none of those proposed changes replaces the rules in force today.
How does SECR differ from ESOS?
SECR is an annual public disclosure of energy use and emissions. ESOS is an energy-assessment regime intended to identify energy-saving opportunities.
Much of the underlying data can be reused. The Government review found businesses already reuse SECR data across ESOS, TCFD and Carbon Reduction Plans, although differences in definitions and boundaries still create duplicated work.
Reuse the data where it genuinely matches. Do not force one reporting boundary onto another scheme simply because it saves a spreadsheet.
How does SECR differ from a Carbon Reduction Plan?
SECR forms part of statutory annual reporting.
Carbon Reduction Plans used for relevant central-government procurement have their own boundaries, emissions categories and publication requirements.
If government procurement is the issue, read our guide to Carbon Reduction Plans.
Where is SECR reported?
Companies normally include SECR information in the Directors’ Report. Large LLPs use an Energy and Carbon Report where applicable.
There is no separate annual SECR filing form.
Can the C Level calculator produce an SECR report?
No.
The Business Carbon Footprint Calculator can help a business assemble an initial operational footprint and expose missing data.
An SECR disclosure also depends on the correct legal reporting entity, the statutory energy coverage, the mandatory travel element, comparative figures, an intensity ratio and the year’s energy-efficiency narrative.
If the figures are going into statutory accounts and the boundary or source data are complicated, I would not treat a self-service calculator as the final answer.
Need the carbon inventory behind your SECR disclosure?
C Level calculates and documents the Scope 1, Scope 2 and relevant Scope 3 emissions that sit behind an SECR disclosure.
We establish the reporting boundary, work through the energy, fuel and travel data, record the UK Government factor set and leave your finance team with the source trail, assumptions and workings behind the result.
We do not prepare or audit the statutory Directors’ Report.
Talk to us about your SECR carbon footprint
Sources and methodology
Every figure in this article was checked against the primary Government sources on 8 September 2026. Nothing here is legal or audit advice.
- DESNZ, 2026 Post-Implementation Review of the SECR Regulations 2018. Source for the recommendation to retain SECR with amendments, the estimate of 14% to 23% non-compliance, the 19% who did not recognise SECR by name, the 94 hours of internal staff time, the £7,100 mean ongoing cost, the warning about an incomplete or UK-only baseline, and the recommendation to consider standardised templates. View the review.
- DESNZ, Streamlined Energy and Carbon Reporting regulations: evaluation. The survey and cost evidence underneath the review, including the non-compliance range and the risk that later Scope 3 reporting makes emissions appear to increase. View the evaluation.
- HM Government, Environmental Reporting Guidelines, including SECR requirements. Source for who must report, the scopes, energy use, intensity ratios, method disclosure, the low energy user exemption, the mandatory business-travel element including reimbursed mileage, the market-based reporting option and what to do where information is not practical to obtain. View the guidance.
- DESNZ, UK Government greenhouse gas conversion factors 2026. Source for the 2026 electricity factor and the 31 July 2026 republication of the flat file. View the factors.
- HM Treasury, Sustainability Reporting Guidance 2025 to 2026. Source for the current threshold figures and for the statement that the April 2025 uplift means SECR no longer aligns with the definition of “large”. View the guidance.
- Department for Education, SECR for academy trusts. The sector-specific application of the same requirements. View the guidance.