What the law requires
Here is where the main UK rules stand in October 2026, and whether any of them reaches a typical small business:
| Rule | Who it covers | Typical SME? |
|---|---|---|
| SECR | Quoted companies, and unquoted companies and LLPs meeting two of: more than 250 employees, over £36m turnover, over £18m balance sheet | No |
| UK SRS | Listed companies, comply or explain, for accounting periods from 1 January 2027; large private companies under consultation until 30 November 2026 | No, and none proposed |
| Companies Act climate-related financial disclosures | Companies and LLPs with more than 500 employees and £500m turnover, and certain others | No |
| ESOS | Large undertakings | No |
So for a business with, say, 40 staff and a few million pounds of turnover, the honest answer is that no law makes you publish your carbon emissions. If you are growing and want to check where you stand on SECR, our SECR checker takes under a minute. Our post on whether small companies need SECR covers the edge cases, and UK carbon reporting requirements lists every rule and who it covers.
Where it becomes a condition of winning work
The requirements that do reach small firms come through buying rules, not company law:
- Central government. Under PPN 006, departments and their agencies must ask bidders for a Carbon Reduction Plan on contracts worth more than £5 million a year including VAT, where relevant and proportionate.
- The NHS. A Net Zero Commitment for NHS contracts below £5 million a year, and a Carbon Reduction Plan at £5 million or more. NHS Supply Chain tenders have needed Evergreen Level 1, which includes a PPN 006 Carbon Reduction Plan, since 6 April 2026, whatever the contract value. Our NHS supplier checker shows which applies to you.
- Other public bodies. Councils, housing associations and universities often ask for a PPN 006-style plan even on small contracts.
- Large customers. Your emissions are part of their Scope 3. Companies measuring their value chain, including listed companies preparing for UK SRS, send supplier questionnaires asking for your figures.
None of these is a legal duty in the way SECR is. But if a buyer you depend on asks, the practical effect can be the same: no plan, no contract. Our guide on what to send when a customer asks for your carbon emissions covers the commercial side.
What's changing
- From 1 April 2027, NHS contracts of £5 million a year or more and all new NHS frameworks need plans covering global operations and all relevant Scope 3. See what changes for NHS suppliers in April 2027.
- From accounting periods starting 1 January 2027, listed companies report against UK SRS on a comply or explain basis, so expect more questions from listed customers about Scope 3.
- Later in 2026, the government has said DESNZ will consult on the future of SECR and ESOS. SECR is unchanged for current reporting years; ESOS phase 4 (qualification date 31 December 2026) has new requirements under the ESOS (Amendment) Regulations 2026.
- From 2030, only suppliers that can show their progress through published progress reports and continued emissions reporting will qualify for NHS contracts.
What a sensible small business does now
- Work out whether you bid for public sector or NHS work, or supply large companies. If you do, you'll be asked.
- Measure Scope 1 and 2 from a year of energy bills and vehicle fuel. Our kWh to CO2e calculator does the conversion with the 2026 government factors.
- Add the five Scope 3 categories a Carbon Reduction Plan asks for: deliveries in and out, waste, business travel and commuting.
- Publish a Carbon Reduction Plan with a net zero commitment by 2050 at the latest, signed by a director. Our free template follows the government format.
- Update it every year, within six months of your financial year end.
Doing this before a tender lands is much easier than doing it in the week it closes, and the same figures answer customer questionnaires too.
