Sustainability certification · United Kingdom
Sustainability certifications: what each one proves, and what it does not
A sustainability certification proves one specific thing about an organisation, and the useful question is which thing.
Some are management-system certificates issued by accredited bodies, some are private marks whose owner sets the rules, and some are standards a claim must conform to.
None is required by UK law, and none discharges SECR or UK SRS; the difference between certification and accreditation is where most confusion starts.
Choose by objective
Which sustainability certification, for which job
Start from what you need to prove, not from the logo.
A tender that asks for an environmental management system wants ISO 14001; a board that wants to commit the whole company to stakeholders is looking at B Corp; a marketing team that wants a neutrality claim needs a conformity route and the advertising rules.
The finder beside this text returns the scheme for each objective, what it proves, what it does not, and the UK duties it leaves untouched.
Two of the routes are written up in depth on this site: ISO 14001 and B Corp certification.
For carbon measurement itself, no certificate is the answer; the inventory is built to the GHG Protocol, often with carbon management software, and Scope 3 under UK SRS covers the value chain.
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Side by side
The main UK sustainability certifications compared
| Scheme | Owner and status | Proves | Does not prove |
|---|---|---|---|
| ISO 14001:2026 | ISO standard; certified by bodies UKAS accredits | A conforming environmental management system | Environmental performance — the standard sets no criteria |
| ISO 50001:2018 | ISO standard; certified by accredited bodies | An energy management system; an ESOS route where it covers total or significant energy | That the ESOS notification has been made |
| B Corp | B Lab’s private certification | B Lab’s V2 requirements across seven Impact Topics; stakeholder governance in the Articles | Compliance with any statute |
| ISO 14068:2026 | ISO standard, replacing ISO 14068-1:2023 | A carbon neutrality claim built on reductions first, then offsetting | That an unqualified claim is safe to advertise |
| Planet Mark | Private scheme, its own Code of Practice | Planet Mark’s reduction test on Scope 1 and 2, normalised, against a rolling baseline | An absolute reduction; accredited certification |
| Carbon Trust Route to Net Zero | The Carbon Trust’s own standard | Progress at one of three tiers; only Leading is 1.5°C-aligned | Science alignment, unless the tier is stated |
| SBTi validation | SBTi’s criteria | That a target was validated at the version in force | That the target will be met |
| EMAS | EU Regulation 1221/2009 | ISO 14001-based system plus a validated public statement | Availability through a UK body |
| FSC, RSPO | Commodity scheme owners | Sourcing and chain of custody for the certified material | Anything about the rest of the business |
The chain
Certification, accreditation and the word “accredited”
ISO defines certification as an independent body’s written assurance that a product, service or system meets requirements, and accreditation as the formal recognition that the certification body is competent (ISO).
ISO itself issues no certificates and says accreditation is not compulsory.
In the UK the accreditation body is UKAS, appointed under SI 2009/3155 regulation 3, and the activities it accredits are listed in its memorandum with DBT.
The government recognises only UKAS accreditation for organisations operating in the UK, and the words “accreditation” and “accredited” in a company name need the Secretary of State’s approval (DBT).
ISO 14001 and ISO 50001 certificates can be accredited; check one on UKAS CertCheck.
B Corp, Planet Mark and the Carbon Trust’s standard are private schemes: their owners set and apply the rules, and none is a UKAS-accredited certification.
That is not a criticism; it means the certificate proves what the owner’s rules say, and you should read those rules.
“ISO certified” — ISO certifies nobody.
“UKAS-accredited consultant” — UKAS accredits bodies, and consultancy is not an activity it accredits.
Carbon neutral and net zero
Carbon neutral and net zero certification: where the standards stand
The most-quoted carbon neutrality credential in the UK no longer exists.
PAS 2060 stopped being delivered from 1 January 2025 and all verifications closed at the end of 2025; an opinion issued for a past period still describes that period but is not a current credential.
Its successor, ISO 14068-1:2023, was withdrawn on 11 September 2026, and ISO 14068:2026 replaces it, with reductions and removals in the value chain ranked ahead of offsetting.
There is no statutory “net zero certification” in the UK.
Private schemes certify progress: the Carbon Trust’s Route to Net Zero Standard, launched on 21 February 2022, has three tiers, and only the top one, Leading, is 1.5°C-aligned, so an untiered claim should be read at the lowest tier it could mean.
Planet Mark certifies on Scope 1 and 2 against a rolling baseline, and its member reports describe a normalised reduction test, so a certificate does not by itself evidence an absolute fall in emissions.
The SBTi validates targets rather than certifying companies, and V2.0 of its net-zero standard can be used for validation from 1 February 2027.
Whatever the certificate, the claim is governed separately: CAP guidance says to avoid unqualified “carbon neutral” or “net zero” claims, and in the EU offset-based product neutrality claims have been unlawful since 27 September 2026 (Directive (EU) 2024/825).
More on the target side is on net zero consultancy.
| Standard | Status |
|---|---|
| PAS 2060 | Withdrawn; verifications closed end-2025 |
| ISO 14068-1:2023 | Withdrawn 11 September 2026 |
| ISO 14068:2026 | The replacement, Carbon neutrality |
| SBTi CNZS V1.3.1 | In force; accepted until 31 January 2028 |
| SBTi CNZS V2.0 | Validations from 1 February 2027 |
Against UK law
What no certification discharges
Every scheme above is voluntary.
The UK’s sustainability reporting duties are not, and they apply on their own tests.
| Duty | Who it applies to | Met by a certificate? |
|---|---|---|
| SECR | Quoted companies; large unquoted companies and LLPs | No |
| ESOS | Large undertakings | Partly, by ISO 50001 covering total or significant energy; the notification is still due |
| UK SRS | Listed companies in UKLR 6, 14, 15, 16 and 22, comply or explain, periods from 1 Jan 2027; voluntary for everyone else | No |
| PPN 006 | Bidders for central government contracts over £5m a year | No — it asks for a Carbon Reduction Plan |
SECR is set out in the government’s SECR guidance and read at the provision on SECR thresholds; how it relates to the UK standards is on SECR and UK SRS.
UK SRS S1 and S2 are the disclosure standards, and this site’s reading of UK SRS S2 covers the climate requirements.
A certificate often makes the evidence for these duties easier to produce; it never replaces the filing.
Before you choose
Questions to ask before you commit to a scheme
- What exactly will the certificate say, and about what — a system, a company, a product or a claim?
- Who owns the rules, and are they published?
- Is the certification accredited, and by whom?
- Which edition or version applies, and when does it change?
- What does it require each year to keep the certificate, and what does the cycle look like?
- Which customer, tender or regulator asked for it, and will that reader accept it?
ISO’s own explainer and B Lab UK’s FAQs answer the first two questions for their schemes; the EMAS Global page answers the EU one.
The Carbon Trust describes its wider work alongside the standard on its own pages.
This site is an independent reference and issues no certificates; readers can book a free 15-minute call to talk a situation through.
Frequently asked
Sustainability certifications: questions people ask
Which sustainability certification is best for a UK business?
It depends on what you need to prove.
ISO 14001 proves an environmental management system and is the one tenders most often ask for.
ISO 50001 proves energy management and is an ESOS route.
B Corp certifies the whole company’s social and environmental performance.
ISO 14068 governs a carbon neutrality claim.
None of them is a substitute for the UK’s statutory reporting duties.
What is the difference between certification and accreditation?
Certification is a body’s written assurance that a product, service or system meets a standard.
Accreditation is the formal recognition that the certification body itself is competent.
In the UK the government recognises only UKAS accreditation.
ISO certifies nobody, and no one accredits consultants.
ISO 14001 vs B Corp vs the Carbon Trust: which is best for manufacturers?
They prove different things.
ISO 14001 is a management-system certificate from an accredited certification body, widely asked for in procurement.
B Corp certifies the whole company against B Lab’s standards and requires a change to the Articles.
The Carbon Trust’s Route to Net Zero Standard certifies emissions progress at one of three tiers.
A manufacturer answering a tender usually needs ISO 14001; the others answer different questions.
ISO 14001 vs PAS 2060: what is the difference?
ISO 14001 certifies an environmental management system.
PAS 2060 was a carbon neutrality specification, now withdrawn: verifications closed at the end of 2025.
Its successor, ISO 14068-1:2023, was itself withdrawn on 11 September 2026 and is being replaced by ISO 14068:2026.
The two were never alternatives.
Is there a net zero certification?
Not in law.
Private schemes certify progress toward net zero on their own terms, such as the Carbon Trust’s Route to Net Zero Standard or Planet Mark’s programme, and the SBTi validates targets rather than certifying companies.
UK advertising guidance warns against unqualified net zero claims.
Are sustainability certifications mandatory in the UK?
No sustainability certification is required by UK law.
Contracts and tenders may require one, most often ISO 14001.
The statutory duties — SECR, ESOS and, for listed companies, UK SRS on a comply-or-explain basis — apply by their own tests and are not met by any certificate, except that ISO 50001 can stand in for parts of ESOS.
How do I check a certificate is genuine?
For an accredited management-system certificate, search UKAS CertCheck, which is free, and check the certification body’s schedule in the UKAS directory.
For B Corp, use B Lab’s directory.
For a private scheme, ask for the scheme owner’s certificate or report and read its basis.
Can a UK company get EMAS?
Not through a UK body.
An organisation outside the EU can register through EMAS Global via the competent body of Finland, Germany, Spain, Italy, Austria, Belgium or Portugal.
Sources
Primary sources
Every figure, date and status on this page traces to the instrument’s owner.
Secondary commentary is never the source for a number.
- ISOCertification — certification and accreditation defined
“ISO does not perform certification”; accreditation “is not compulsory”.
- Department for Business and TradeAccreditation — guidance (updated 16 March 2026)
Government recognises only UKAS accreditation in the UK; “accredited” is a sensitive word in a company name.
- legislation.gov.ukThe Accreditation Regulations 2009 (SI 2009/3155), regulation 3
- Department for Business and TradeDBT–UKAS Memorandum of Understanding 2023, Appendix 1
The activities UKAS accredits.
- United Kingdom Accreditation ServiceUKAS CertCheck
- ISOISO 14001:2026 — catalogue record
No environmental performance criteria (Clause 1).
- ISOISO 14001 explained
- United Kingdom Accreditation ServiceISO 14001:2026 transition bulletin
UK transition by 30 April 2029.
- ISOISO 50001 — energy management
- legislation.gov.ukESOS Regulations 2014 (SI 2014/1643), Schedule 1
- B LabB Lab Standards V2 — performance requirements
- B Lab UKFAQs
- ISOISO 14068:2026 — Carbon neutrality
Replacing ISO 14068-1:2023, withdrawn 11 September 2026.
- BSIPAS 2060 — withdrawn
Verifications closed at the end of 2025.
- Planet MarkNet Zero Certification Programme
Planet Mark’s own terms for its own certification.
- The Carbon TrustRoute to Net Zero Standard
Three tiers; only Leading is 1.5°C-aligned.
- The Carbon TrustWhat we do
- Science Based Targets initiativeCorporate Net-Zero Standard V2.0 and transition dates
- European CommissionEMAS Global
Registration for organisations outside the EU, through seven member states.
- Forest Stewardship Council UKFSC UK
- Roundtable on Sustainable Palm OilRSPO
- Committee of Advertising PracticeAdviceOnline — Carbon offsetting and carbon neutral
- EUR-LexDirective (EU) 2024/825 — Annex I points 4a and 4c
- Department for Business and TradeEnvironmental reporting guidelines, including SECR guidance
- Department for Business and TradeUK SRS S1 and UK SRS S2
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