B Corp climate requirements for small firms

Under B Lab's V2 standards, which all B Corp submissions now use, a micro, small or medium company must publish a climate action plan with time-bound targets, approved by its board or senior management, from the start, then show and publicly report progress from year 3. A measured, independently verified Scope 1, 2 and 3 footprint and science-based targets are only required of large companies and above.

Updated 19 October 2026 by the Carbon Recycling team. Figures use the official UK government conversion factors and are checked against the current gov.uk guidance.

What changed with the new standards

B Lab published new B Corp standards on 8 April 2025, and B Lab UK says all certification submissions are now on them (V2). Instead of collecting points across a long assessment, companies must meet minimum requirements in seven Impact Topics. Climate Action is one; Environmental Stewardship and Circularity, which covers wider environmental impacts such as waste and resources, is another. Certifications are now checked by a third-party assurance provider.

Requirements scale with company size. Size is set by the lower of your full-time-equivalent workers and your revenue, a rule B Lab adopted in November 2025 to stop smaller firms being pushed into bigger categories.

Climate Action requirements by size

Requirement	Micro, small, medium and no-worker companies	Large, extra large and extra extra large
Measure Scope 1, 2 and 3 every year and publish the results (CA1.1)	Not required	From year 0
Independent verification of the inventory (CA1.2)	Not required	From year 0
Publicly available climate action plan (CA2.1)	From year 0	Not required: a climate transition plan from year 3 instead (CA2.3)
Science-based targets, validated or independently verified (CA2.2)	Not required	From year 3
Make progress on the plan and evaluate it (CA3.3)	From year 3	Transition plan progress from year 5
Publicly disclose progress (CA3.6)	From year 3	Annually, from year 5

Large companies also have requirements on a just transition, executive pay and, for the very largest, climate advocacy.

What the climate action plan needs

B Lab's guidance for smaller companies takes a deliberately practical line: an accurate, verified footprint is the gold standard, but requiring one up front would be a disproportionate burden, and most small firms already know their biggest sources. So the plan focuses on targets for actions. It should include, in proportion to your size:

clear, time-bound targets that are specific and measurable;
the main emission sources you considered;
the concrete actions you will take;
who is responsible internally;
how you will track progress.

It must include a commitment to support limiting global warming to 1.5°C, be approved by your highest governing body (the board, chief executive or general management), be published on your website or somewhere stakeholders can see it, and be updated every three years. B Lab suggests the sources most small firms should look at first: purchased electricity, business travel, employee commuting, purchased goods and services, waste, and even where the company banks and where staff pensions are invested.

An action target with a number behind it

Suppose your plan says: "By the end of 2027, staff will travel by train instead of their own cars for journeys between our offices." If those journeys add up to 10,000 miles a year in an average car, the 2026 government factors put them at 2.67 tonnes CO2e. The same distance by national rail is 0.50 tonnes, a cut of about 81%, or 2.17 tonnes a year.

B Lab doesn't require you to show that sum, but doing it is what turns a list of good intentions into a plan you can prioritise. It tells you which actions are worth the effort, and it means that when you do measure your footprint, your targets are already in tonnes.

Should a small firm measure anyway?

Usually, yes, for reasons outside B Corp:

Customers ask. Large customers need their suppliers' figures for their own Scope 3. See our guide on what to send when a customer asks for your carbon data.
Public tenders need it. A PPN 006 Carbon Reduction Plan requires measured Scope 1, 2 and five Scope 3 categories.
You may grow into it. Move up a size category and the footprint, verification and science-based targets become requirements. A few years of consistent figures make that step much easier. Our guide to science-based targets for SMEs explains what's involved.

For how B Corp fits alongside other schemes customers ask about, see our posts on EcoVadis carbon questions and ISO 14001 and your footprint.

How Carbon Recycling helps

Carbon Recycling measures your Scope 1, 2 and 3 emissions from bills, mileage, travel and waste records with the UK government factors, so you can see your biggest sources and put a tonnes figure against each action in your plan. Its Carbon Reduction Plan report holds your baseline, targets and actions in a document a director signs off and you publish on your website, which covers much of what B Lab asks of a public climate action plan. Each year's figures then show the progress you report from year 3.

Frequently asked questions

Does a small B Corp have to measure its carbon footprint?

Not under the Climate Action topic of B Lab's V2 standards. Micro, small and medium companies, and companies without workers, must publish a climate action plan with time-bound targets. A Scope 1, 2 and 3 inventory, third-party verification and science-based targets are required of large, extra large and extra extra large companies.

What must a small company's climate action plan include?

B Lab's guidance lists clear, time-bound targets, the main emission sources considered, concrete actions, who is responsible, and how progress will be tracked. It must be approved by the company's highest governing body, be publicly available, and be updated every three years.

Can the targets be about actions instead of tonnes?

Yes. For smaller companies B Lab focuses on targets for actions that cut emissions, such as switching to renewable electricity by a date, rather than requiring tonnes-based reduction targets. Companies that can measure and verify their emissions are encouraged to set targets in tonnes.

When do the Climate Action requirements apply?

For smaller companies the public climate action plan is needed from the start (year 0). Making and evaluating progress on it, and publicly reporting that progress, apply from year 3 of certification.

How is company size decided?

By the lower of your number of full-time-equivalent workers and your revenue. B Lab switched to this 'lesser of two' rule in November 2025, which moved some companies into a smaller size category with fewer requirements.

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