The rules on carbon reporting reach fewer businesses than the headlines suggest. But the questions reach almost everyone sooner or later: a customer's supplier form, a tender, a bank, a buyer for the business or a new recruit asking what you are doing about climate change. This guide is for businesses that aren't required to report, want to know whether they should, and want to do it properly.
Who isn't legally required to report
Here is where the main UK rules stand in October 2026, and who they leave out:
| Rule | Who it covers | Who it leaves out |
|---|---|---|
| SECR | Quoted companies, and unquoted companies and LLPs meeting two of: 250 or more employees, £36m turnover, £18m balance sheet | Unquoted companies and LLPs meeting at most one of those, sole traders and ordinary partnerships |
| PPN 006 | Bidders for central government contracts worth more than £5 million a year, where relevant and proportionate | Anyone not bidding for central government contracts of that size, though other public buyers often ask for a similar plan |
| NHS supplier rules | NHS suppliers: a Carbon Reduction Plan above £5 million a year, a Net Zero Commitment below, and Evergreen Level 1 for NHS Supply Chain tenders since 6 April 2026 | Businesses that don't sell to the NHS |
| UK SRS | Listed companies, comply or explain, for accounting periods from 1 January 2027; large private companies under consultation | Everyone else, and nothing proposed would change that for most businesses |
| ESOS | Large undertakings, with 250 or more employees, or turnover over £44 million and a balance sheet over £38 million | Everyone below those sizes (and ESOS is an energy audit, not a carbon report) |
Our SECR checker confirms where you stand in under a minute, and our post on whether carbon reporting is mandatory covers the edge cases. If you have sites outside the UK, our country pages show what reporting looks like in each place we cover.
Why businesses report anyway
Without a legal duty, the reasons are commercial. Most come down to someone you depend on wanting a number from you, or you wanting a number to make better decisions.
- Customers measuring their supply chain. Your emissions are part of your customer's Scope 3. A customer with a net zero or science-based target needs figures from its suppliers to show progress, and it may have a target for how many suppliers set targets of their own. Our post on why a customer's net zero target becomes questions for you explains the mechanics, and what customers can reasonably ask suppliers covers where the line is.
- Tenders and frameworks. Councils, housing associations, universities and large private buyers often ask for a PPN 006-style Carbon Reduction Plan or a carbon question in the quality score, even on contracts well under £5 million.
- NHS suppliers. Every new NHS procurement asks for a Net Zero Commitment or a Carbon Reduction Plan, whatever the size of your business. Our NHS supplier checker shows which applies.
- Platforms your customers use. EcoVadis, CDP's supply chain programme and similar questionnaires score carbon. See our posts on the EcoVadis carbon questions and answering a CDP supply chain request.
- Lenders. Green loans and sustainability-linked loans need evidence. A sustainability-linked loan ties the interest margin to targets, such as cutting Scope 1 and 2 emissions, and the Loan Market Association's principles expect a baseline and yearly reporting. Our post on what lenders ask for under green loans has the detail.
- Insurers and landlords. These are more often about climate risk, such as flooding and overheating, than about carbon, but the questions tend to arrive together. Our climate risk guide covers that side.
- Investors and buyers of the business. Due diligence questionnaires often include environmental questions. A footprint with a clear method, kept up to date, is easier to hand over than one assembled in a hurry during a sale.
- Staff and recruitment. Some candidates ask what an employer is doing about climate change. A measured footprint and a plan give a factual answer instead of a slogan.
- Energy costs. Measuring shows where the energy goes, and energy is usually most of a footprint. Cutting it lowers bills as well as emissions: see our worked examples for LED lighting and heat pumps.
- Standards and certifications. B Corp needs a climate action plan with targets, ISO 14001 now asks you to consider climate change, and EcoVadis credits measured figures.
What level of reporting fits
You don't need to do everything at once. Match the work to who is asking and what they will do with it.
| Your situation | What to produce |
|---|---|
| Nobody has asked yet, but you want to be ready | A first Scope 1 and 2 footprint for your latest 12 months, from your gas and electricity bills and vehicle fuel or mileage. Our kWh to CO2e calculator gives a first figure in minutes. |
| A customer has sent a questionnaire | Scope 1 and 2, the period, method and factor year, any Scope 3 you have, and your share for that customer if asked. See what to send when a customer asks and how to word the answers. |
| Several customers ask the same questions | A one-page customer summary you can send to everyone, or publish on your website, so every answer matches. |
| Tenders, frameworks or the NHS | A Carbon Reduction Plan in the PPN 006 format, with Scope 1, 2 and the five Scope 3 categories it asks for, and a net zero commitment. Our free template follows the government format. |
| Customers with science-based targets, EcoVadis or a lender's KPI | Scope 3 by category, starting with purchased goods and services, a reduction target with a base year, and a record of progress each year. Our Scope 3 categories guide shows which matter for your business. |
Whichever level you start at, use the same method every time: the GHG Protocol, the UK government conversion factors for each year, and a stated boundary. That way a later, fuller report builds on the first one instead of replacing it. Our guide to calculating a business carbon footprint walks through each step.
How long it takes
- Collect a year of data. Gas and electricity bills or meter readings, fuel cards or mileage claims, and any heating oil or bottled gas. This is usually the slowest part, especially for businesses with several sites or landlord-supplied energy.
- Work out Scope 1 and 2. Multiply each quantity by the matching government factor and add them up. With the data in hand, this takes hours, not weeks.
- Add Scope 3 over time. Business travel, commuting, waste and deliveries can come from records you already keep. Purchased goods can start with spend-based estimates from your purchase ledger and improve as suppliers share figures.
- Write a short plan. A base year, a target, the main actions and who is responsible. A Carbon Reduction Plan does this in a format buyers recognise.
Most businesses have a first Scope 1 and 2 footprint within a few weeks of starting, and a Carbon Reduction Plan soon after. Before you send anything out, our free report check recalculates the electricity and gas figures and lists anything a PPN 006 plan or SECR report would expect that is missing.
Talking about it without breaking the Green Claims Code
Measuring your emissions is something to be proud of, and it's fine to say so. The risk is in how. The CMA's Green Claims Code says environmental claims must be truthful, clear, complete, fair, consider the full life cycle and be backed by evidence, and since April 2025 the CMA can fine a business up to 10% of its global turnover for misleading consumers. The CMA says its examples generally apply where one business markets to another, too. Our post on what the Green Claims Code means for your marketing covers it in full.
- Say what you measured. "We measured our Scope 1 and 2 emissions for the year to March 2026: 48 tonnes CO2e, using the UK government conversion factors" is specific and checkable.
- Say what you are doing. "We plan to cut Scope 1 and 2 by 30% by 2030 from that baseline, starting with our vans" is a commitment you can report against.
- Don't claim to be carbon neutral or net zero. Measuring doesn't remove emissions, and offset-based "carbon neutral" claims are the kind the CMA and the ASA challenge. Net zero is a future target, not a current state. See net zero and carbon neutral explained.
- Don't imply an endorsement you don't have. Calling a target "science-based" means validated by the SBTi to most readers, so describe an unvalidated target as it is.
- Keep the evidence. The bills, the factors and the calculation, so you can show how you got the number if anyone asks.
Raising awareness inside the business
A voluntary report does most good when people see it. Share the footprint with staff, say where most of it comes from, and ask for ideas on the biggest items: heating, vehicles, travel or what you buy. Put the target and the yearly figure where people will see them, and report progress honestly, including years when emissions go up because the business grew. When customers ask, you will already have the answer, and the same figures will be ready if a law or a contract does start to apply.
How Carbon Recycling helps
Start with the free tools: the kWh to CO2e calculator for a first Scope 1 and 2 figure, the supplier questionnaire answer bank for model answers to the commonest customer questions, and the report check for a plan or report you already have.
When you want the full picture, Carbon Recycling turns your bills, fuel, travel and spend into Scope 1, 2 and 3 figures with the government factors for each year, and produces a Carbon Reduction Plan, an SECR report and an EU VSME report from the same data, so every answer you give matches. The 14-day free trial needs no card: you can add your data and see your reports, though printing and downloading them needs a plan. Plans start at £59 a month plus VAT (see pricing).