ESOS vs SECR: What's the Difference?

Two distinct regulatory frameworks

ESOS and SECR address different aspects of UK organisational sustainability. ESOS requires 4-yearly energy audits to identify cost-effective efficiency opportunities. SECR mandates annual energy and carbon disclosure within company accounts.

Neither regime replaces the other. Large organisations typically face obligations under both frameworks, with overlapping but distinct compliance requirements.

Side-by-side comparison

Qualification differences

ESOS qualification

ESOS applies to "large undertakings" meeting specific size criteria on 31 December 2026:

• Employee test: 250 or more employees in UK group, OR
• Financial test: Annual turnover exceeding £44 million AND balance sheet total exceeding £38 million (both required)

Group aggregation rules mean a single qualifying entity brings the entire UK group into scope.

SECR qualification

SECR applies to different entity types with distinct thresholds:

• Quoted companies: All UK-listed companies regardless of size
• Large unquoted companies: Meeting 2-of-3 tests — £36m+ turnover, £18m+ balance sheet, 250+ employees
• Large LLPs: Same 2-of-3 tests as unquoted companies

The lower SECR thresholds capture a broader population than ESOS, including many medium-sized entities.

Compliance interaction

ESOS audit feeds SECR narratives

SECR energy efficiency action narratives provide the recognised vehicle for ESOS participants to report annual progress against their action plans.

ESOS Phase 4 introduces mandatory action plans and annual progress updates. Organisations subject to both regimes can satisfy this requirement through their SECR disclosure.

Data reuse opportunities

Both frameworks require energy consumption data, creating efficiency opportunities:

• Buildings energy use: ESOS audit scope overlaps with SECR disclosure requirements
• Emissions factors: ESOS intensity ratios can inform SECR GHG calculations
• Efficiency actions: ESOS opportunities directly support SECR action narratives

Do you need both?

Likely subject to both regimes

Large UK organisations typically fall under both frameworks:

• FTSE 350 companies: Quoted status triggers SECR; size likely triggers ESOS
• Large private companies: Often exceed both ESOS and SECR size thresholds
• UK subsidiaries of overseas groups: Group aggregation may bring both into scope

ESOS only

Organisations meeting ESOS thresholds but not SECR qualification:

• Private companies with 250+ employees but under SECR financial thresholds
• Groups with high turnover and balance sheet but under 250 employees (failing SECR's 2-of-3 test)

SECR only

Organisations subject to SECR but not ESOS:

• Quoted companies below ESOS size thresholds
• Medium-sized companies meeting SECR's 2-of-3 test but not ESOS thresholds

Timeline coordination

ESOS 4-yearly cycle

• Qualification assessment: 31 December 2026
• Audit period: 12 months within 24 months ending 5 December 2027
• Compliance deadline: 5 December 2027

SECR annual cycle

• Reporting period: Financial year (typically 12 months)
• Filing deadline: 6 months (PLCs) or 9 months (private companies) after year-end
• Disclosure location: Directors' report within annual accounts

Organisations can time ESOS audits to align with SECR reporting periods, maximising data reuse and narrative coordination.

Penalty frameworks

ESOS enforcement

ESOS penalties are civil sanctions under the Regulatory Enforcement and Sanctions Act 2008:

• Audit failure: Up to £50,000 plus £500 daily
• Notification failure: Up to £5,000 plus £500 daily
• Public register: Non-compliance details published

SECR enforcement

SECR operates through Companies Act 2006 filing requirements:

• Late filing penalties: £150-£7,500 depending on delay and company size
• Directors' liability: Section 418 creates potential criminal liability for knowing non-compliance
• FRC oversight: Disclosure quality monitoring without direct penalties

Looking ahead: Phase 5 alignment

ESOS Phase 5 planning includes threshold alignment with SECR to reduce regulatory fragmentation. This change, originally planned for Phase 4, was deferred to allow focus on enhanced reporting requirements.

Future alignment may create a more coherent regulatory landscape while maintaining distinct ESOS audit and SECR disclosure functions.