What a sustainability consultancy does
A sustainability consultancy helps an organisation measure its environmental impact, report it to the standard each regime requires, and reduce it over time.
In the UK the work is anchored in statutory and listing-rule reporting rather than voluntary marketing.
The foundation is a greenhouse-gas inventory built on the SECR regime (SI 2018/1155)3 and the UK Government conversion factors.
From that single data set, our sustainability consultants produce the figures behind SECR, ESOS, TCFD and UK SRS.
Good sustainability consulting is therefore less about strategy slides and more about defensible numbers: emissions that reconcile, methodologies that are documented, and disclosures that survive board and auditor scrutiny.
The UK regimes
UK sustainability reporting is a stack of overlapping regimes.
A capable consultancy maps which apply to you and sequences them by deadline.
| Regime | What it requires |
|---|---|
| SECR | Energy and carbon in the Directors’ Report (SI 2018/1155) |
| ESOS Phase 4 | Energy audits; notification by 5 Dec 2027 |
| TCFD → UK SRS | Climate disclosure migrating to UK SRS S2 |
| UK SRS S1 / S2 | Sustainability and climate disclosure |
The newest of these, the UK Sustainability Reporting Standards1, were published by the Department for Business and Trade on 25 February 2026.
Under FCA CP26/52, UK SRS S2 is proposed to be mandatory for in-scope listed companies from 1 January 2027.
Choosing sustainability consultants
When you compare sustainability consultants, the differentiator is methodology, not vocabulary.
Ask which standards underpin the work and how the outputs will be assured.
Look for consultants who calculate emissions on the GHG Protocol, apply the annual DESNZ conversion factors for UK reporting, and build to the specific frameworks behind each regime.
Ask how a single inventory will feed SECR, ESOS and UK SRS so you are not paying to measure the same thing three times.
Our method
Carbon Legal works in three stages: a gap assessment against every applicable regime, a prioritised roadmap sequenced by deadline and materiality, and delivery of the disclosures with the figures prepared for assurance.
The same emissions data set runs through SECR, ESOS Phase 4 and UK SRS S2, which keeps the figures consistent and the cost of compliance down.
How we help
As your sustainability consultancy, we confirm scope, build the inventory with our emissions compliance consultants, and draft each disclosure in the required format.
For reduction and target-setting, our net zero consultancy takes the same data forward.
Carbon Legal is a specialist sustainability consultancy, not a law firm, and does not provide legal advice.
We launch in Q3 2026 and are booking readiness reviews now.
Frequently asked questions
What does a sustainability consultancy do?
A sustainability consultancy helps an organisation measure, report and reduce its environmental impact, and meet the disclosure rules that apply to it. In the UK that means working across SECR, ESOS, TCFD and the new UK Sustainability Reporting Standards (UK SRS), plus the underlying greenhouse-gas inventory. The consultancy calculates the figures, drafts the disclosures each regime requires, and prepares the organisation for assurance.
What is the difference between a sustainability consultancy and sustainability consultants?
They describe the same service from different angles. A sustainability consultancy is the firm; sustainability consultants are the specialists who do the work. At Carbon Legal the consultants are specialists in UK energy and emissions reporting rather than generalists, so engagements stay focused on compliance-grade outputs.
How do I choose a sustainability consultant in the UK?
Look for consultants who work to recognised methodologies — the GHG Protocol for emissions, the UK Government (DESNZ) conversion factors for UK reporting, and the specific frameworks behind each regime (SI 2018/1155 for SECR, the ESOS guidance, and UK SRS S1 and S2). Ask how the same data set will be reused across regimes, and how the figures will stand up to assurance.
Do sustainability consultants help with mandatory reporting?
Yes. The core of UK sustainability consulting is statutory and listing-rule reporting: SECR in the Directors’ Report, ESOS energy audits, and climate disclosure under UK SRS S2, which is proposed to be mandatory for in-scope listed companies from 1 January 2027 under FCA CP26/5.
When should we engage a sustainability consultancy?
Before the reporting year, not at filing. Most disclosures depend on a full year of energy and emissions data, so the measurement work needs to start early. Carbon Legal launches in Q3 2026 and is booking readiness reviews now.
Sources
Authority sources
Continue reading