Business growth
ESG v B Corp: what's the difference - and does your SME actually need either?
Start with an ESG policy, not B Corp certification. ESG costs nothing but discipline, while B Corp adds audit, annual fees and a change to your Articles.
By David ElliottBSc FCA, Founder & Managing PartnerFigures in this piece were checked on 14 August 2026. Rates and thresholds change, so confirm anything you are relying on.
If you’ve been hearing “ESG” and “B Corp” used almost interchangeably, you’re not alone - and you’re not wrong to be confused. They’re related, but they’re not the same thing, and mixing them up can lead SMEs to either overspend on formal certification they don’t need or underinvest in groundwork they do.
Here’s the practical difference, and an honest look at which businesses get real value from each.
ESG - a strategy, not a certificate
ESG stands for “Environmental, Social and Governance” and it’s a framework for how a business manages its environmental impact, how it treats its people and its supply chain, and how it governs itself ethically.
Crucially, ESG isn’t a certification you apply for. There’s no badge, no “pass” or “fail” assessment and no fixed fee. It’s a strategy your business defines for itself, covering things like carbon reduction, ethical sourcing, health & safety, diversity, and business ethics; it then reports on these, honestly, over time.
That flexibility is both its strength and its risk. Because nobody audits your ESG policy externally, it only has value if you actually implement it and can evidence progress. A polished ESG statement with no data behind it won’t survive a client or funder asking follow-up questions.
However, because getting an ESG policy and strategy in place is an internal process for your business, there’s nothing to stop you from doing this now – at zero cost – and getting your ESG policy displayed prominently on your website.
B Corp - ESG formalised and audited
B Corp Certification, awarded by the non-profit organisation B Lab, takes the same underlying territory (environmental and social performance, governance, community and customers) and turns it into an externally verified, legally binding certification. Since B Lab’s standards overhaul (fully in effect for all new applicants from January 2026), certification requires meeting mandatory baseline performance across every one of these areas - so, no more excelling in one area to offset weakness in another, as the old points-based system allowed.
Two things make B Corp a bigger commitment than an ESG policy:
A legal change
UK companies must amend their Articles of Association to embed a stakeholder-focused purpose alongside shareholder value; this is not optional, and not quick to unwind once done.
Independent audit
From 2026, an accredited third-party assurer verifies your claims, replacing the old self-assessment model; this not only adds rigour, but also cost and lead time.
Who actually benefits from each?
Micro and small businesses (revenue of below £250k and 1-20 staff)
A clear, honestly-implemented ESG policy is usually the right starting point – and is often the right end point too. B Corp’s legal and audit requirements are, arguably overkill for a business this size, unless certification itself is core to your brand (this may be the case if you’re selling, for example, consumer-facing ethical products) or if a specific client is demanding it.
Growing SMEs (roughly £250k-£2m turnover and 20-50 staff)
This is where ESG stops being optional in practice. Public sector and larger-corporate supply chains increasingly expect evidenced ESG credentials at tender stage and the UK’s Procurement Act 2023 has pushed “social value” considerations further into public contract evaluation. A well-evidenced ESG policy pays for itself here. B Corp becomes worth evaluating rather than pursuing outright - particularly for consumer brands or businesses competing on values as a differentiator.
Established SMEs (£2m - £10m+ turnover and 50-200 staff)
At this size, you’re likely already fielding ESG questionnaires from clients, investors, or insurers; an ESG policy is close to essential. B Corp starts to make commercial sense too, especially in sectors where few competitors hold it (an instant differentiator) or where investor conversations reward it. The revenue-scaled fee structure for certification and audit also becomes proportionally more manageable at this size.
The cost reality
An ESG policy has no fixed external fee; the cost is your own time (or a consultant’s) to research, write, and, most importantly, resource the implementation. Underestimating that internal cost is the most common mistake; a policy nobody acts on is worse than no policy at all, since it can look like greenwashing if scrutinised.
B Corp has published, revenue-banded fees (frozen through 2026 to support the transition to new standards): businesses with revenue under £150,000 pay a modest one-off submission fee; a business with revenue of £150-500k pays roughly £1,250 annually; for revenue of £500k-£1m the cost is around £1,500 annually plus a small one-off fee. On top of that, you should budget for legal costs to amend your Articles, staff time on the assessment itself, and independent audit fees. Realistically, it will take 6-12 months of work before certification lands.
The bottom line
Start with ESG, regardless of your business’s size, as it’s the foundation that everything else sits on, and it costs nothing but discipline. Only move to B Corp once your ESG groundwork is genuinely in place and you have a clear commercial reason (tender requirements, brand differentiation or investor pressure) to justify the legal commitment and the recurring cost. Chasing the badge before the substance is the single most common and most expensive mistake SMEs make.
Next week we’ll look at ISO v Investors in People - two very different certifications that SMEs often confuse - and which of them actually fits your business.