SECR vs ESOS — what's the difference?

SECR and ESOS are two separate UK energy and carbon reporting schemes that often catch the same large companies — but they are not the same thing. SECR is an annual energy and carbon report filed inside your Directors' Report at Companies House. ESOS is a four-yearly mandatory energy assessment — in effect an energy audit — submitted to the Environment Agency. The qualifying thresholds differ, the regulators differ, and complying with one does not satisfy the other. This guide explains the key differences between ESOS and SECR in plain UK English, so you know exactly what your business must do.

What is SECR?

SECR (Streamlined Energy and Carbon Reporting) is an annual carbon reporting scheme: a disclosure of your UK energy use, scope 1 and scope 2 greenhouse gas emissions, at least one intensity ratio and an energy efficiency narrative. SECR reporting is filed inside your Directors' Report with your annual accounts at Companies House. SECR was introduced on 1 April 2019, replacing the CRC Energy Efficiency Scheme and broadening mandatory greenhouse gas reporting well beyond the quoted companies already caught by earlier rules.

SECR aims to bring energy and carbon information into mainstream financial reporting, make energy use and carbon emissions visible to investors, lenders and customers, and increase awareness of energy waste so each business can improve energy efficiency year on year. Companies in scope must calculate their total energy consumption and report on their energy use to help drive year-on-year savings. Because the disclosure rides inside the directors' report, SECR follows an annual rhythm tied to your accounts. See what is SECR and who needs SECR.

What is ESOS?

ESOS stands for the Energy Savings Opportunity Scheme — a four-yearly mandatory energy assessment and energy saving identification scheme. It requires a large undertaking to audit its total energy consumption across buildings, transport and industrial processes, identify cost-effective energy saving opportunities, and submit a notification of compliance to the Environment Agency (or the devolved regulator). ESOS is the UK's implementation of Article 8 of the EU Energy Efficiency Directive. ESOS is mandatory for large undertakings; it is not a voluntary reporting scheme.

The ESOS assessment must be reviewed and signed off by an approved ESOS lead assessor — a competent person on a recognised register. ESOS aims to drive energy efficiency by making large organisations aware of where energy is wasted; SECR aims to disclose energy use and carbon emissions. Where SECR discloses, ESOS audits. See our ESOS reporting page for the full process.

What is included in an ESOS assessment?

A compliant ESOS assessment must cover at least 90% of your total energy consumption — the significant energy use across your buildings, transport fleet and processes. In practice an ESOS energy audit involves four things: measuring total energy use across the qualifying period, identifying where that energy is consumed, calculating cost-effective energy saving opportunities with payback periods, and having an ESOS lead assessor confirm the work before you notify the Environment Agency. You can demonstrate compliance through ESOS-compliant energy audits, an ISO 50001 energy management system, Display Energy Certificates, or a mix of routes.

SECR vs ESOS — the key differences at a glance

This is where companies trip up: SECR and ESOS use different qualification tests, run on different cycles, report to different regulators, and are signed off by different people. The table below sets out the key differences between ESOS and SECR.

Who needs to comply with ESOS and SECR?

The SECR thresholds and the ESOS thresholds are different, so being required to comply with SECR does not automatically mean you are caught by ESOS, and vice versa.

SECR applies to a company that meets two of three tests: annual turnover of £36 million or more, an annual balance sheet total of £18 million or more, or 250 or more employees. Note the wedge created by the April 2025 Companies Act uplift: the general definition of a "large" company rose to £54 million turnover and £27 million balance sheet, but the SECR thresholds did not move. So a company now classed as medium-sized for ordinary accounts purposes can still face compliance with SECR. Don't assume a reclassification takes you out of scope.

ESOS applies to large undertakings: any UK organisation with 250 or more employees, or with annual turnover over £44 million and an annual balance sheet total over £38 million. Because the ESOS turnover test is higher than SECR's, some companies are in scope for SECR but not ESOS — another reason to check each scheme on its own facts.

Check your SECR position in 30 seconds with the free SECR eligibility checker.

What are the reporting requirements for ESOS and SECR?

The reporting requirements differ in both content and destination.

SECR reporting requires you to report, inside the directors' report alongside your financial statements: your total energy consumption in kWh (electricity, gas and transport fuel), your scope 1 and scope 2 greenhouse gas emissions in tonnes of CO2 equivalent, at least one intensity ratio, the energy efficiency measures taken in the reporting year, and the methodology used. Quoted companies report global figures; large unquoted companies and LLPs report their UK energy use. Scope 3 emissions remain voluntary. Calculate your figures with the free carbon calculator and current DEFRA conversion factors.

ESOS is built around different requirements: a compliant energy audit covering at least 90% of total energy consumption, work to identify energy waste and surface opportunities for energy savings, sign-off by an ESOS lead assessor, and a notification of compliance to the Environment Agency. From the 2023 (phase 3) cycle onwards, ESOS also requires participants to set out an action plan and report progress against the savings they identified — a clear push to act each year to cut energy use, not just measure it.

How do ESOS and SECR overlap?

Both schemes are mandatory energy and carbon reporting obligations, and many large companies are caught by both. The energy data feeds across: the total energy consumption you calculate for ESOS supports your SECR figures on energy consumption and carbon emissions, and an ESOS energy audit surfaces exactly the energy efficiency measures and carbon reduction actions you then point to in the SECR energy efficiency narrative. Treating both as one environmental reporting programme cuts duplication — align data collection to a single reporting year so the same energy usage figures serve each scheme, and many companies use one specialist to manage both.

But the obligations, regulators, deadlines and reporting periods are separate. Completing your ESOS assessment does not satisfy SECR, and filing SECR does not discharge your ESOS duty — SECR runs every reporting year, ESOS every four years, so you must track each deadline independently rather than assume one covers the other.

What are the deadlines for ESOS and SECR?

SECR has no separate deadline of its own. Because the disclosure sits in the directors' report, it is filed on your accounts deadline at Companies House: 9 months after the financial year-end for private companies and LLPs, 6 months for public companies. Work out your exact date with the free deadline calculator.

ESOS works in four-year phases, each with a single compliance date by which the assessment must be completed and notified to the Environment Agency. Missing the SECR deadline risks Companies House late-filing penalties and a Companies Act breach; missing the ESOS deadline risks civil penalties from the Environment Agency. See our SECR filing deadlines guide for the SECR side in full.

Are there penalties for non-compliance with ESOS or SECR?

Yes — both schemes carry penalties, but they are enforced differently. Under SECR, leaving the required disclosure out of the directors' report is a criminal offence under the Companies Act 2006, with unlimited fines on conviction and every director personally liable; delaying your accounts to fix a SECR gap also triggers Companies House late-filing penalties. See SECR penalties for the detail. Under ESOS, the Environment Agency can impose civil penalties for failing to undertake an energy assessment, failing to notify, or failing to keep adequate records — including fixed and daily penalties, plus publication of the breach. In both cases the cost of getting it wrong far exceeds the cost of doing it properly the first time.

Can ESOS lead to cost savings for your business?

This is the upside that gets overlooked. ESOS exists to identify cost-effective energy saving opportunities, and a thorough energy audit routinely surfaces measures that reduce energy consumption, cut energy costs and lower carbon emissions. Acting on those opportunities turns a compliance exercise into a genuine return — and the energy savings you achieve are exactly the energy efficiency improvements you then report under SECR, supporting any wider carbon reduction or net zero target.

SECR vs UK SRS — what is coming next

A separate question is starting to come up: will SECR be replaced by the UK Sustainability Reporting Standards (UK SRS)? UK SRS are the UK's adoption of the ISSB's IFRS S1 (general sustainability disclosures) and IFRS S2 (climate disclosures). They are a broader, investor-focused framework — not just energy and carbon — and not yet a mandatory filing obligation for most companies. The practical takeaway: SECR is not optional or paused while UK SRS is developed. Keep meeting your SECR obligation, and treat the data discipline you build now as a head start. The scope 1 and scope 2 emissions you report for SECR will feed straight into S2 reporting if and when it applies, alongside material scope 3 emissions and your net zero planning.

How to get started with ESOS and SECR compliance

Start by confirming which schemes apply to you, then map both clocks: your annual SECR filing date and your ESOS phase compliance date. For SECR, gather a full reporting year of energy consumption data, calculate scope 1 and scope 2 greenhouse gas emissions with the current conversion factors, choose an intensity ratio, and draft the disclosure for the directors' report. For ESOS, commission an energy audit covering 90% of total energy use and engage an ESOS lead assessor early. The single biggest mistake is gathering the data too late — start a few months ahead and both obligations stay calm rather than a year-end scramble.

Which applies to your business?

Check your SECR position in 30 seconds with the eligibility checker, work out your filing date with the deadline calculator, then let us match you with a vetted, IEMA-qualified SECR specialist who can confirm both your SECR and ESOS obligations. We are an introduction service — we do not file on your behalf or sell you software — so you get the right person for your sector and size. It is free to talk and there is no obligation. Get matched with a specialist when you are ready.