Which UK organisations need to comply with ESOS, SECR and UK SRS?

Large organisations may be in scope of all three regimes. ESOS applies to organisations with 250+ employees or (£44m+ turnover AND £38m+ balance sheet). SECR applies to large companies with £36m+ turnover or £18m+ balance sheet or 250+ employees. UK SRS S2 will apply to premium listed and large PIE companies from January 2027.

ESOS, SECR and UK SRS — How the UK Energy Reporting Regimes Work Together

ESOS, SECR and UK SRS S2 are the three UK reporting regimes covering energy and carbon. Understanding how they overlap, who's in scope of which, and how to manage them together with a single data infrastructure.

ESOS Phase 4: Dec 2027UK SRS S2: Jan 2027SECR: Ongoing

The Three UK Regimes in 60 Seconds

Regime	Scope	Frequency	Output	Regulator	Next Deadline
ESOS Phase 4 250 employees OR (£44m turnover + £38m balance sheet)	UK large undertakings	4-yearly cycle	Energy audit + Action Plan	Environment Agency + devolved	5 December 2027
SECR £36m turnover OR £18m balance sheet OR 250 employees	Large companies	Annual (Directors' Report)	Energy & carbon disclosure	Companies House filing	6 months after year-end
UK SRS S2 Premium listing or Large PIE status	Premium listed + large PIEs	Annual (sustainability report)	Climate-related financial disclosure	FCA supervision	From January 2027

Who's In Scope of What — Three Scenarios

ESOS only

Large private companies, partnerships, LLPs that meet ESOS thresholds but not SECR/UK SRS

Example:

Private group with 300 employees, £30m turnover, not listed

Obligations:

ESOS audit every 4 years. No annual carbon reporting required.

SECR + ESOS

Large companies that meet both sets of thresholds but aren't premium listed or large PIEs

Example:

AIM-listed company with £50m turnover, 400 employees

Obligations:

Annual SECR in Directors' Report + ESOS audit every 4 years

All three regimes

Premium listed companies and large PIEs that also meet ESOS/SECR thresholds

Example:

FTSE 350 company with significant UK operations

Obligations:

UK SRS S2 climate disclosure + annual SECR + ESOS audit every 4 years

The Data Overlap — Same Meter Readings, Different Presentations

The three regimes require substantially similar underlying data but present it differently. Most large organisations end up collecting the same energy and emissions data multiple times rather than building integrated systems.

Data Type	ESOS	SECR	UK SRS S2
Scope 1 emissions	✓ Required for audit baseline	✓ Mandatory disclosure	✓ Core climate metric
Scope 2 emissions	✓ Required for audit baseline	✓ Mandatory disclosure	✓ Core climate metric
Scope 3 emissions	○ Optional (some categories)	○ Optional (large companies)	✓ Mandatory (from 2028)
Energy consumption	✓ Central to audit requirement	✓ Mandatory disclosure	○ Context for climate metrics
Energy efficiency measures	✓ Action Plan requirement	○ Narrative disclosure	○ Transition planning context
Financial impacts	✓ Business case for measures	○ Optional commentary	✓ Financial materiality focus

The Regulators — Different Authorities, Different Approaches

ESOS Regulators

England: Environment Agency
Wales: Natural Resources Wales (NRW)
Scotland: Scottish Environment Protection Agency (SEPA)
Northern Ireland: DAERA/NIEA

Enforcement: Civil penalties up to £50,000 for non-compliance

SECR Oversight

Primary: Companies House filing requirement
Policy: Department for Business and Trade (DBT)
Enforcement: Companies Act 2006 framework

Penalties: Criminal liability under s463 for directors

UK SRS Supervision

Primary: Financial Conduct Authority (FCA)
Standards: Department for Business and Trade (DBT)
Assurance: Financial Reporting Council (FRC)

Enforcement: FCA supervision and disciplinary powers

The 2026–2027 Timing Pressure

Critical Window: UK SRS S2 becomes mandatory in January 2027, just before ESOS Phase 4 compliance deadline in December 2027. Organisations in scope of both need to coordinate data collection and avoid duplicating effort.

2026 Preparation Year

31 Dec 2026: ESOS Phase 4 qualification date. Organisations must assess whether they meet the thresholds.
Throughout 2026: UK SRS S2 preparation for January 2027 mandatory reporting. First climate disclosures due.
Ongoing: Annual SECR compliance in Directors' Reports. No respite from existing obligations.

2027 Compliance Year

January 2027: UK SRS S2 climate disclosures become mandatory. First reporting cycle begins.
5 December 2027: ESOS Phase 4 compliance deadline. Energy audits, Action Plans and notifications due.
Risk: Organisations scrambling to meet multiple deadlines with overlapping data requirements but separate teams.

Where DESNZ Has Signalled Rationalisation

DESNZ Consultation Response (2024): "DESNZ will consider how energy and emissions data reported by an entity using UK SRS interacts with the SECR requirements, with a view to reducing unnecessary duplication where possible."

What's Been Signalled:

• Recognition that UK SRS S2 and SECR create data duplication
• Commitment to "consider" interactions and reduce duplication "where possible"
• Acknowledgment that large companies will be in scope of both regimes

What Hasn't Been Decided:

• Whether ESOS will be included in the rationalisation review
• Timeline for any changes to reporting requirements
• Whether cross-reference between regimes will be permitted
• Impact on existing SECR statutory requirements in Companies Act 2006

Planning Assumption: Until further guidance is published, organisations should plan for full compliance with all three regimes separately. Any rationalisation is likely to be incremental and take several years to implement.

How to Manage All Three with One Data Infrastructure

Common Data Foundation

Energy consumption data

Meter readings, invoices, calculated consumption by fuel type and site

Required for all three regimes

Scope 1 & 2 emissions

Calculated from energy data using published emission factors

Core requirement across ESOS, SECR and UK SRS

Organisational boundaries

Financial control, operational control or equity share methodologies

Must be consistent but can vary between regimes

Baseline and historical data

Multi-year datasets for trend analysis and target setting

ESOS needs 12+ months, SECR needs annual, UK SRS needs trends

Regime-Specific Outputs

ESOS

4-yearly

Energy audit report + Action Plan

Lead Assessor sign-off, energy efficiency opportunities, business case analysis

SECR

Annual

Directors' Report disclosure

Energy and carbon figures, methodology note, energy efficiency measures

UK SRS S2

Annual

Climate-related financial disclosure

TCFD-aligned governance, strategy, risk management, metrics and targets

Integration Best Practice

Technology Integration:

• Single energy and emissions database
• Automated data validation and QA processes
• Report generation from common dataset
• Version control and audit trails

Governance Integration:

• Single sustainability/ESG team ownership
• Coordinated external advisor procurement
• Shared assurance and verification processes
• Integrated compliance calendar and deadlines

Explore Each Regime

ESOS Resources

Energy Savings Opportunity Scheme guidance

→ ESOS thresholds and qualification → Phase 4 timeline and deadlines → Is ESOS mandatory?→ ESOS vs SECR comparison

SECR Resources

Streamlined Energy and Carbon Reporting

→ SECR thresholds and scope → Filing deadlines and penalties → Is SECR mandatory?→ SECR vs UK SRS comparison

UK SRS Resources

UK Sustainability Reporting Standards

→ UK SRS S1 and S2 overview → UK SRS timeline and deadlines → Mandatory reporting timeline → UK SRS for financial services

ESOS Services

Professional support and consultancy

→ ESOS reporting services → Finding ESOS consultants → ESOS assessment costs

Sources and Further Reading

Government Sources

GOV.UK ESOS Guidance ESOS Regulations 2014 (SI 2014/1643)ESOS Phase 4 Amendment (SI 2023/1182)SECR Regulations 2018 (SI 2018/1155)UK SRS S1 and S2 Publication (Feb 2026)ESOS Post-Implementation Review 2025

Professional Bodies & Standards

Energy Managers Association (EMA)CIBSE Lead Assessor Certification BSI PAS 51215-1:2025 (Energy Assessment Process)FRC UK SRS Technical Advisory Committee