Choosing an adviser · UK
Emissions compliance consultants: which adviser does which job
“Emissions compliance consultants” covers at least seven different kinds of adviser, and only two of them hold a credential the law recognises.
An ESOS lead assessor must be on an approved register, and a UK ETS verifier must be accredited by UKAS to ISO 14065.
Everyone else — the carbon footprint consultant included — is chosen on evidence, and this page sets out what evidence to ask for.
Start with the rule
The rule decides which adviser you need
Behind the labels — carbon advisory, footprint consulting, net zero strategy — the core of emissions compliance work is narrow and technical.
It turns activity data into a defensible greenhouse gas number, and then into whatever a particular rule demands.
Which rule applies is the first question, and the carbon compliance consultancy guide has a checker covering nine UK regimes.
SECR sends the number into the directors’ report under the 2018 Regulations, and SECR requirements explains who is in scope.
ESOS sends energy data into a four-yearly assessment, with notification due on 5 December 2027 for ESOS Phase 4.
The UK ETS sends it into a verified report and a surrender of allowances every spring, as GOV.UK’s participation guidance sets out.
A listed company in UKLR 6, 14, 15, 16 or 22 reports against UK SRS on a comply-or-explain basis for periods beginning on or after 1 January 2027, under the FCA’s final rules that finalised CP26/5.
Each route needs a different mix of skills, which is why the adviser question comes second.
Fix the regime first, then the boundary and method, then the adviser.
Hiring the adviser first means paying them to answer a question you could answer from your own accounts.
Seven kinds of adviser
Who does what, and what credential exists
| Adviser | What they produce | Credential the law recognises | Where it is needed |
|---|---|---|---|
| Carbon footprint consultant | A Scope 1, 2 and 3 inventory for an organisation or product | None required; ISO 14064-1 or the GHG Protocol as method | Customer questionnaires, PPN 006, SBTi baselines, UK SRS S2 data |
| Carbon compliance adviser | Which regimes apply, and the disclosures they ask for | None required | SECR, the Companies Act climate disclosures, UK SRS, UK CBAM |
| ESOS lead assessor | Oversight and sign-off of an ESOS energy assessment | Membership of one of seven approved registers | ESOS Phase 4 |
| UK ETS monitoring adviser | Monitoring plans, data systems, verification readiness | None required | UK ETS installations, aircraft and ships |
| UK ETS verifier | The verification opinion on the annual emissions report | A body accredited by UKAS to ISO 14065 | UK ETS |
| Permitting and air-quality consultant | Environmental permits, emission limit values, monitoring | None required; the permit is the regulator’s | EPR 2016, medium combustion plant, the Pollution Inventory |
| Assurance provider | A limited or reasonable assurance opinion on reported figures | Depends on the provider; no UK register is live | Voluntary assurance of SECR, UK SRS or CDP data |
One firm may offer several of these roles, and there is nothing wrong with that as long as it does not assure its own work.
The deliverable each regime asks for is laid out regime by regime in carbon compliance services.
Carbon footprint consultants
The footprint is the input to almost everything
A carbon footprint consultant measures emissions, and most carbon footprint experts work to one of two methods.
The GHG Protocol Corporate Standard sorts emissions into Scope 1 (direct), Scope 2 (purchased energy) and Scope 3 (the rest of the value chain, in fifteen categories).
ISO 14064-1:2018 specifies organisation-level quantification and reporting and is deliberately neutral between programmes; ISO has marked it for revision.
Either can produce a sound footprint, and neither makes the consultant who uses it certified.
Scope 3 is where most of the difficulty and most of the hours sit, and it is where the FCA’s rules give listed companies a one-year relief; Scope 3 reporting under UK SRS goes deeper.
The standard itself is explained in ISO 14064, and the scopes in Scope 1, 2 and 3 emissions.
What a footprint must state
| Item | Why it matters |
|---|---|
| Standard | GHG Protocol or ISO 14064-1 for an organisation |
| Boundary | Financial control, operational control or equity share |
| Scope 2 method | Location-based for UK SRS; market-based as extra information |
| Scope 3 coverage | Which of the fifteen categories, and why |
| Factor set | The DESNZ year matching the activity data |
Credentials
What the letters after a name actually test
For every role except the ESOS lead assessor and the UK ETS verifier, credentials are voluntary, so it helps to know what each one assessed.
| Credential | Who awards it | What it tests |
|---|---|---|
| ESOS lead assessor | One of seven approved registers (AEE, CIBSE, Elmhurst, Energy Institute, EMA, ISEP, Quidos) | Competence to PAS 51215:2014, the standard regulation 12 names |
| UK ETS verifier | UKAS accreditation of the verification body | The body’s competence to ISO 14065 for the activity reported |
| ISEP Affiliate | Institute of Sustainability and Environmental Professionals (formerly IEMA) | Nothing — a paid sign-up with no eligibility requirements |
| ISEP Associate, Practitioner, Full | ISEP | An exam or course, then written competence evidence, and for Full a peer interview |
| Chartered Environmentalist (CEnv) | Society for the Environment, through a licensed member body | Eleven competences at master’s level, by degree or equivalent written work |
The seven registers and the regulation that recognises them are the only credential UK law requires anywhere in this field.
Membership of one of those seven bodies is not the same as being on its ESOS register, so ask which register, and check it.
UKAS accredits bodies — laboratories, certification, inspection and verification bodies — under the Accreditation Regulations 2009; a consultant described as “UKAS-accredited” is being described wrongly.
The Institute of Environmental Management and Assessment changed its name to ISEP in January 2025, so older post-nominals such as MIEMA are out of date rather than invalid.
Environmental compliance
When “emissions” means a permit, not a footprint
For a site with boilers, engines or process plant, emissions compliance often means environmental permitting rather than carbon reporting.
The Environmental Permitting (England and Wales) Regulations 2016 govern permits for installations, waste operations and discharges, and extend to England and Wales only; Scotland and Northern Ireland run their own instruments.
Medium combustion plant is where many mid-sized sites meet the regime: an existing plant of 1 to 5 megawatts needs a permit by 1 January 2029 under regulation 12(1A), and must meet emission limit values a year later under Schedule 25A.
The Environment Agency’s Pollution Inventory is not an automatic duty on every permit holder; it rests on a notice under regulation 61.
These limits cover pollutants such as nitrogen oxides as well as carbon, and the skills are air-quality engineering rather than greenhouse gas accounting.
A site with more than 20 megawatts of rated thermal input is also inside the UK ETS, which is where the two kinds of emissions adviser meet.
| Existing medium combustion plant | Permit by | Emission limits from |
|---|---|---|
| Over 5 MW thermal input | 1 Jan 2024 | 1 Jan 2025 |
| 1 to 5 MW thermal input | 1 Jan 2029 | 1 Jan 2030 |
Independence
Keep the preparer and the checker apart
Where figures will be checked, the adviser who builds them and the body that checks them should be different.
For management system certification, ISO/IEC 17021-1 bars a certification body from offering management system consultancy, with a two-year bar in each direction.
For UK ETS reports, the verifier is an accredited body with its own impartiality rules.
For SECR and UK SRS, assurance is voluntary: the FRC issued ISSA (UK) 5000 in November 2025 for voluntary use, and the FCA’s rules ask only for a statement of what was obtained.
How assurance works when a company chooses it is in sustainability assurance in the UK.
No UK entity is required to obtain sustainability assurance.
The FRC issued ISSA (UK) 5000 for voluntary use, and the FCA asks listed companies only to say whether assurance was obtained and by whom.
In-house or adviser
For some of this, and not for all of it
| Task | In-house often works | An adviser often adds value |
|---|---|---|
| SECR Scope 1 and 2 | Yes — metered data, repeatable method | Method and boundary in the first year |
| ESOS assessment | Data gathering and site access | Lead assessor oversight, unless one is on staff |
| Full Scope 3 inventory | Rarely at first | Category screening, estimation, supplier data |
| UK ETS monitoring | Routine collection | Monitoring plan and verification readiness |
| Medium combustion plant permit | Rarely | Application, emission limits and monitoring |
| Assurance readiness | Partly | An audit trail a third party can follow |
Straightforward SECR reporting from metered energy is often manageable in-house once a method is set, because the data already exists in bills and fleet records.
ESOS is different: in most cases a registered lead assessor must oversee the assessment, so outside input is built into the scheme unless you employ one.
The Environment Agency’s ESOS guidance lists the registers to check.
Choosing
Seven questions for any emissions adviser
Which rule creates this work for us, and which instrument sets each threshold you have quoted?
Which standard and boundary will you use, and will the Scope 2 figure be location-based?
Who will sign what — and for ESOS, which approved register is the lead assessor on?
Will you also verify or assure the figures you prepare? (The right answer is no.)
Do you earn anything from the remedies you recommend — offsets, equipment, software?
Who owns the data and the model at the end, and in what format?
What will the second year cost, and what makes it cheaper?
No price appears on this page: no regulator publishes one for emissions advice, and a market range is not a sourced figure.
A longer set of nine questions, with what a good and a weak answer sound like, is on the carbon compliance consultancy page.
This site is an independent reference and supplies none of these services; to talk through which adviser you need, book a free 15-minute call or go back to the home page.
Frequently asked
Emissions compliance consultants: questions answered
What does an emissions compliance consultant do?
An emissions compliance consultant helps an organisation meet a rule that makes it measure, report, verify or limit emissions. Depending on the rule that means building a greenhouse gas inventory for SECR or UK SRS, overseeing an ESOS energy assessment, preparing UK ETS monitoring and verification, or handling an environmental permit for emissions to air. They are different jobs, and one firm rarely does all of them well.
What is a carbon footprint consultant?
A carbon footprint consultant measures an organisation’s or product’s greenhouse gas emissions — Scope 1, Scope 2 and Scope 3 under the GHG Protocol, or to ISO 14064-1 for an organisation or ISO 14067 for a product. The footprint is the input to most carbon regimes. The role has no protected title and no register in the UK.
Is there a register of emissions compliance consultants?
Not for the advice itself. The ESOS lead assessor is the one role UK law ties to a register: the lead assessor must sit on one of seven approved registers kept by professional bodies. UK ETS verification is controlled differently: the verifier is a body accredited by UKAS to ISO 14065, not an individual consultant. UKAS does not accredit consultants.
What qualifications should a carbon footprint consultant have?
None is legally required. Useful signals are an assessed professional grade — for example Practitioner or Full membership of the Institute of Sustainability and Environmental Professionals (formerly IEMA), or Chartered Environmentalist status from the Society for the Environment — plus the ability to name the standard and boundary they will use. Affiliate membership of ISEP involves no assessment and is not a competence credential.
Do I need a consultant for ESOS?
ESOS needs a lead assessor on an approved register to oversee the assessment, unless ISO 50001 covers the organisation’s total or significant energy consumption or total consumption is below 40,000 kWh. The lead assessor can be an employee. Many organisations hire one because they do not have a registered assessor on staff.
Can the same firm build our inventory and verify it?
It should not. For certification against management system standards, ISO/IEC 17021-1 bars a certification body from offering management system consultancy. For UK ETS reports, the verifier must be an accredited body. Even where assurance is voluntary, as it is for SECR and UK SRS, keeping the preparer and the checker separate is what makes an assurance opinion worth having.
What is environmental compliance consulting, as opposed to carbon?
Environmental compliance usually means permits: emissions to air, water discharges and waste under the Environmental Permitting (England and Wales) Regulations 2016, including medium combustion plant. Those rules cover pollutants such as nitrogen oxides and particulates as well as carbon. An existing medium combustion plant of 1 to 5 megawatts needs a permit by 1 January 2029 and must meet emission limit values from 1 January 2030.
How do I choose an emissions compliance consultant?
Start with the rule that creates the work, because that decides which kind of adviser you need. Then ask each shortlisted firm to name the instrument behind every threshold it quotes, the standard and boundary it will use, who will sign what, whether it has any commercial interest in the remedies it recommends, and what the second year will cost.
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.
- GHG ProtocolCorporate Accounting and Reporting Standard
Scope 1, 2 and 3; the basis of most inventories.
- ISOISO 14064-1:2018 — organisation-level GHG quantification and reporting
GHG-programme neutral; marked for revision by ISO.
- ISOISO 14065:2020 — bodies validating and verifying environmental information
The standard UK ETS verifiers are accredited to.
- legislation.gov.ukThe Accreditation Regulations 2009 (SI 2009/3155)
Appoints UKAS as the national accreditation body — which accredits bodies, not consultants.
- ISOISO/IEC 17021-1:2015 — bodies providing audit and certification of management systems
The separation of certification from consultancy.
- legislation.gov.ukSI 2018/1155 — the SECR Regulations, as made
The instrument that created SECR.
- legislation.gov.ukSI 2008/410, Schedule 7, Part 7A
SECR scope and content for unquoted companies and LLPs.
- Environment AgencyEnergy Savings Opportunity Scheme (ESOS) — guidance and approved registers
The seven approved lead assessor registers.
- legislation.gov.ukSI 2014/1643, regulation 12 — approved registers
The register mechanism and the PAS 51215 competence standard.
- GOV.UKParticipating in the UK ETS
Verified annual report and surrender dates.
- legislation.gov.ukEnvironmental Permitting (England and Wales) Regulations 2016, regulation 1
Extent: England and Wales only.
- legislation.gov.ukEPR 2016, regulation 12(1A)
Medium combustion plant permit deadlines.
- legislation.gov.ukEPR 2016, Schedule 25A
Medium combustion plant emission limit value dates.
- legislation.gov.ukEPR 2016, regulation 61
The notice power behind the Pollution Inventory.
- Financial Reporting CouncilFRC takes steps to support quality and consistency in the assurance of sustainability reporting (November 2025)
ISSA (UK) 5000 issued for voluntary use.
- Financial Conduct AuthorityPS26/19 — final rules on UK SRS for listed companies
Comply or explain; a statement about assurance if obtained.
- Financial Conduct AuthorityCP26/5 — the consultation PS26/19 finalises
The proposals, including the mandatory S2 limb that did not survive.
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