Mandatory energy audit: who is covered in 2026?

Since 2014, the regulatory energy audit had been a matter for large companies: at least 250 employees, or more than €50 million in turnover and €43 million in balance sheet total. Since 1 October 2025, the criterion is energy consumption: every company whose average consumption over the last 3 years reaches 2.75 GWh must carry out an audit every 4 years, the first by 11 October 2026. From 23.6 GWh, an ISO 50001-certified energy management system is required by 11 October 2027.

The switch moves the boundary: an industrial SME with 80 employees that heats, dries or cools can become subject to the requirement, while a services company with 400 employees in offices can leave it. The law’s impact assessment did not quantify the number of SMEs covered, and no official list identifies them: each company must calculate it from its energy and vehicle fuel bills.

1Since October 2025, energy consumption replaces size

The regulatory energy audit is a standardised assessment of a company’s consumption: where energy goes, building by building, process by process and vehicle by vehicle, and which actions would reduce consumption, ranked by profitability. It has existed in France since 2014; the 2025 reform mainly changes the list of companies required to carry it out.

The old criterion: company size

The regime arising from the 2012 European directive targeted large companies: at least 250 employees, or more than €50 million in turnover and more than €43 million in balance sheet total, over 2 consecutive financial years. They had to carry out an audit every 4 years, unless ISO 50001-certified. This criterion ignored actual consumption: a consultancy with 300 employees was subject to it, while a foundry with 150 employees and €30 million in turnover was exempt.

The 2 thresholds in the 2025 law

Directive (EU) 2023/1791 on energy efficiency replaced size with consumption, and France transposed it through Law No. 2025-391 of 30 April 2025, known as DDADUE, which entered into force on this point on 1 October 2025. The new Article L. 233-1 of the Energy Code sets 2 thresholds calculated from average annual final energy consumption:

• From 2.75 GWh: an energy audit every 4 years, unless the company has implemented a certified energy management system.
• From 23.6 GWh: a certified energy management system compliant with ISO 50001, replacing the audit.

In the 2 cases, the company must then establish an action plan and publish it in its annual report, the main new feature of the 2025 law for companies already accustomed to audits. The thresholds convert those in the directive, expressed in terajoules: 10 TJ for the audit, 85 TJ for the management system.

The companies and associations covered

The requirement covers legal persons registered in the Trade and Companies Register, but also non-commercial private-law legal persons carrying out an economic activity referred to in Article L. 612-1 of the Commercial Code. Under that article, these exceed 2 of the 3 thresholds of 50 employees, €3.1 million in resources and €1.55 million in balance sheet total, including many associations managing establishments. For companies, no workforce or turnover threshold remains, whereas most environmental requirements depend on size. Public bodies fall under a separate regime requiring them to reduce consumption each year by at least 1.9% of its 2021 level.

The scale of the switch remains poorly understood: according to the bill’s impact assessment, published in October 2024, 55% to 75% of large companies already covered would exceed 10 TJ, around 4,000 companies in ADEME’s first estimate, while the number of SMEs above the threshold "has not yet been determined".

2The 3 calculation rules that determine whether you are covered

The decree of 29 December 2025 sets calculation rules that often change the result: they add vehicle fuels and self-consumption to the total, but also divide groups into companies.

An average over 3 calendar years, covering all energy sources

The consumption used is the average of the preceding 3 calendar years, without the legislation identifying the years for the first deadline. The European Commission’s guidelines assess the 2025 requirement using 2022-2024, while a literal reading of the decree, in force since January 2026, points to 2023-2025: if either of the 2 averages reaches 2.75 GWh, the audit is due in 2026, and 11 October remains the most prudent date.

The average adds all final energy sources: electricity, gas, fuel oil, steam or district heat, and vehicle fuels, as the decree of 29 December 2025 covers "all activities" of the legal person. For a haulier, calculation starts from fuel card statements, the same data used for a road haulier’s Bilan Carbone®, and a fleet already covered by greening requirements also contributes to this total. Electricity produced by solar panels and self-consumed on site also counts.

Bills express natural gas in kWh GCV (gross calorific value), while public statistics count final energy in NCV (net calorific value); according to SDES, 1 kWh GCV equals 0.9 kWh NCV. A litre of diesel or domestic fuel oil represents around 10 kWh NCV. The decree refers calculation details to an order that had not been published as of 28 September 2026: a company close to the threshold should therefore recalculate the total with gas counted as billed, in GCV, increasing this source by around 11%.

Calculation by legal person, identified by its SIREN

The threshold is assessed at legal person level, identified by its SIREN number: sites of the same company are added together, while a group’s subsidiaries are counted separately. A company operating 12 shops adds their consumption. Conversely, a group owning 5 subsidiaries consuming 1.5 GWh each has none covered, despite consuming 7.5 GWh in total. Legal structure therefore matters as much as technology, and merging 2 subsidiaries can be enough to bring a company into the requirement.

What 2.75 GWh represents on a bill

At average prices paid by French companies in the second half of 2025 according to Eurostat, excluding VAT, 2.75 GWh costs around €333,000 excl. VAT for electricity alone and €192,000 excl. VAT for gas alone, each in its consumption band. A company splitting this energy equally between the 2 falls into smaller bands with a higher price per kWh, and pays closer to €350,000 excl. VAT. A company whose energy and vehicle fuel spending exceeds €200,000 excl. VAT a year should therefore calculate precisely; below €150,000, the threshold is rarely reached.

3Deadlines: 11 October 2026 for the audit, 11 October 2027 for ISO 50001

The applicable date depends on the company’s situation before the reform and its consumption level.

Newly covered companies

A company not covered by the old regime that reaches 2.75 GWh must carry out its first audit by 11 October 2026, then renew it every 4 years. From 23.6 GWh, it must have a certified energy management system by 11 October 2027.

Above 23.6 GWh, the legislation leaves an ambiguity: Article L. 233-1 only exempts companies from the audit once they have implemented this system, which would also impose the October 2026 deadline on those that have not. DREAL Grand Est, by contrast, presents the 2 dates as alternatives, and European Commission examples do not provide for an interim audit. Without official clarification, an audit before 11 October 2026 remains the safest position.

Companies already covered by the old regime

A large company already carrying out audits that remains above 2.75 GWh continues its 4-year cycle: it renews its audit when the currently valid one expires. If its consumption is below the threshold, it leaves the requirement, even with 1,000 employees, as DREAL Grand Est notes.

Those crossing the threshold later

A company whose consumption increases has one year after the 3 calendar years of exceedance to comply: if its 2026-2028 average reaches 2.75 GWh, the audit is due during 2029. Activity growth, a new kiln or bringing a fleet in-house can therefore create the requirement.

What replaces the audit

An ISO 50001-certified energy management system covering at least 80% of consumption replaces the audit. The December 2025 decree adds 2 equivalents: an ISO 14001-certified environmental management system incorporating a compliant energy audit, and an energy performance contract, whose conditions must be set by an order we had not found published as of 28 September 2026. ISO 14001 certification without an integrated energy audit is insufficient.

4What the audit must contain, and who may carry it out

Regulatory audit content is set by an Order of 10 July 2025, which also overhauled auditor recognition.

At least 80% of consumption, under NF EN 16247

The audit must cover at least 80% of the company’s final energy consumption, a criterion replacing 80% of bill value since the December 2025 decree. It follows NF EN 16247-1, 2022 version, supplemented as appropriate by its building, process and transport parts. A company operating similar buildings, such as a branch network, may audit only a sample: at least the square root of the number of sites, with a quarter selected randomly, meaning 7 visits for 49 branches.

The detail required for processes

On an industrial site, the audit reaches at least level 2 of the standard and details each use accounting for more than 10% of site consumption, with a minimum of 3 uses studied: kiln, steam boiler, refrigeration plant or air compressors, as applicable. It characterises process temperature levels and waste heat releases, and assesses renewable and recovered energy use. Submetering gathered for this purpose also serves a production site’s Bilan Carbone®, and studying a refrigeration plant often intersects with refrigerants covered by the F-Gas Regulation.

A certified provider, or a qualified internal auditor

The audit is carried out either by an external provider certified for the audited field or by internal personnel meeting the order’s criteria: independence from the audited activity and technical leads with 2 to 5 years’ experience depending on their qualification. Provider certification replaced the old qualification scheme: the Ministry for the Ecological Transition cites AFNOR Certification, LNE and OPQIBI, which received operational admissibility from COFRAC allowing them to issue a regulated number of certificates. Providers qualified under the old regime remain recognised until 30 June 2027, a period extended by one year by a decree of 29 June 2026.

5After the audit, an action plan published in the annual report

This is the most consequential new feature of the 2025 law: the audit now leads to a public action plan, which the company’s clients, employees and shareholders can read.

The company develops this plan from audit recommendations or its energy management system. It lists measures to implement for each recommendation where technically or economically possible, and any measure paying for itself in less than 5 years that is not implemented must be justified. The approved plan is published in the annual report, with its implementation rate, and made publicly available while respecting trade secrets.

An order must still specify the action plan’s content and had not been published as of 28 September 2026; the law nevertheless already applies, including the 5-year rule. For a company subject to BEGES or the CSRD, this plan should align with its climate transition plan.

Submission to the administration within 2 months

Within 2 months of the audit or ISO 50001 certification, the company submits on ADEME’s platform (audit-energie.ademe.fr) the information listed by the Order of 20 May 2016, amended on 2 July 2026: company and establishment consumption over 4 years, the share of consumption covered by the audit, provider certification number, breakdown between buildings, processes and transport, and waste heat release temperatures for industry. The consumption declaration, mandatory above 2.75 GWh, is made simultaneously on the same platform.

6What does a company risk if it has not carried out its audit?

Inspection rests with regional state services, DREAL, which rely on platform submissions.

The procedure begins with a formal notice, allowing time to comply. Without a response, the administration may impose an administrative fine capped at 2% of turnover excluding taxes for the last closed financial year, rising to 4% for a repeat offence, under Article L. 233-4 of the Energy Code. For an SME with €20 million in turnover, the cap reaches €400,000, more than the cost of ten audits. Since 2025, the same regime applies to a missing consumption declaration.

Energy savings certificates conditional on the audit

The less familiar risk is financial: since 1 January 2026, a company subject to the requirement can no longer obtain energy savings certificates (CEE) for a specific operation installing fossil-fuel-powered equipment, in industry for example, unless its audit has been carried out and its action plan published and implemented by the application date.

7Where to start if the deadline is near or has passed

Whether the 11 October 2026 deadline is a few days away or has already passed, the issue is the same: launch the audit without waiting for an inspection and document every step.

• Reconstruct consumption from 2022 to 2025, company by company, from electricity, gas and fuel oil bills, fuel card statements and self-consumed solar generation; ADEME’s platform requests 4 years.
• Check the legal scope: which group companies cross the threshold, and which buildings, processes or vehicles each operates.
• Consult recognised providers, requesting the certificate number, or qualification under the old regime, and the field covered: buildings, processes or transport.
• Prepare site data: submetering, installed power, operating hours and site plans.
• Organise the action plan: who approves it, which annual report will publish it and how to track its implementation rate.

There is no official price schedule, but the law’s impact assessment estimated an audit’s cost in 2024 at between €5,000 for a simple installation, such as an office building, and €30,000 for a complex installation. According to ATEE, which manages the PRO-SMEn grant, a CEE-funded programme cannot help a company fulfil a regulatory requirement, and this ISO 50001 certification grant has accepted no new registrations since 1 October 2025. Recommended works remain in principle eligible for CEE and other transition grants.

The energy audit and Bilan Carbone® complement one another

The audit measures kilowatt-hours and quantifies savings; Bilan Carbone® measures tonnes of CO2e across the whole value chain, including scope 3. Consumption collected for the audit directly feeds scopes 1 and 2 of the assessment, while audit actions feed the reduction pathway expected by regulatory BEGES, the CSRD or an SBTi approach. Our energy audit or Bilan Carbone® comparison details what each covers, and the process of an industrial SME’s Bilan Carbone® describes site data collection, including energy bills.

For us at Projet Celsius, the costliest mistake is commissioning the audit as a filing formality: its action plan will be published and monitored each year, and benefits from being built alongside the emission reduction pathway, using the same data. For an SME without an assessment yet, Diag Décarbon'Action reduces its cost, and our Bilan Carbone® support starts from energy data already gathered for the audit.

8Key takeaways

• Since 1 October 2025, the regulatory energy audit depends on final energy consumption; workforce and turnover no longer count.
• From 2.75 GWh average annual consumption over 3 years: first audit by 11 October 2026, then every 4 years; from 23.6 GWh: certified ISO 50001 by 11 October 2027.
• Calculation is by legal person, including all energy sources: vehicle fuels, heat, self-consumed solar; a group does not add its subsidiaries together.
• The audit follows NF EN 16247 over at least 80% of consumption; it is carried out by a certified provider, a qualified provider until 30 June 2027 or an internal auditor.
• An action plan published in the annual report follows the audit, justifying unimplemented measures paying for themselves in less than 5 years; breaches expose the company to a fine of up to 2% of turnover.

Commercial buildings of at least 1,000 m² are also covered by the tertiary decree and BACS decree, and the future carbon price on fuels and heating will make the fossil energy that the audit helps reduce more expensive. To place the audit among other requirements, our overview of CSR requirements by company size reviews them.

Further resources

Frequently asked questions

1My company has fewer than 250 employees: is it covered by the mandatory energy audit?

Yes, if its average annual final energy consumption reaches 2.75 GWh over the last 3 calendar years: since 1 October 2025, neither workforce nor turnover counts. Calculation adds electricity, gas, fuel oil, heat, vehicle fuels and self-consumed solar energy at company level. The first audit is due by 11 October 2026.

2Is ISO 50001 mandatory?

Yes, from 23.6 GWh average annual consumption: an ISO 50001-certified energy management system must be in place by 11 October 2027 for newly covered companies. Below that level, certification remains voluntary and exempts the company from the audit if it covers at least 80% of its energy consumption.

3Must a group add its subsidiaries’ consumption together?

No: the threshold is assessed for each legal person, identified by its SIREN number. A subsidiary exceeding 2.75 GWh is covered even if the rest of the group consumes little, while subsidiaries all below the threshold are not covered, even if the group’s total substantially exceeds it.

4What does a company without an energy audit risk?

After an ineffective formal notice, an administrative fine of up to 2% of turnover excluding taxes for the last closed financial year, and 4% for a repeat offence. Since January 2026, a missing audit also blocks some energy savings certificates for operations installing fossil-fuel-powered equipment.

5How much does a regulatory energy audit cost?

There is no official price schedule: the 2025 law’s impact assessment estimated an audit’s cost at between €5,000 for a simple installation, such as an office building, and €30,000 for a complex industrial site. CEE-funded grants cannot pay for the mandatory audit, but recommended works remain eligible in principle.

6Is this the same audit as for selling a house?

No: the audit required when selling a home rated E, F or G, then D from 2034, falls under the Construction Code and covers housing. The company audit falls under the Energy Code, follows NF EN 16247 and depends on company consumption. The tertiary decree is another separate requirement, imposing consumption reductions on commercial buildings of at least 1,000 m².

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