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 and the SBTi SME route 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.
