Mandatory energy audit: who is concerned and what to do?

Who is subject to the mandatory energy audit?

Any company whose average annual final energy consumption exceeds 2.75 GWh. Consumption is calculated over the last three years, at company level (SIREN) and across all energies. This criterion replaced the former size threshold, which targeted large companies with over 250 employees or exceeding certain turnover and balance-sheet thresholds: medium-sized companies, sometimes with a small structure, are now concerned if they consume a lot.

The table summarises the three situations. Dates are those announced by the texts; confirm them on the energy ministry website or on the ADEME platform before setting your schedule.

What if the 2026 deadline has passed?

Start the audit without delay. The energy code provides for penalties in case of non-compliance, and a late audit is still better than no audit. First check that you are concerned by calculating your three-year average consumption, then choose a qualified auditor and declare the situation on the ADEME platform.

Allow a few weeks: collecting bills and meter readings, the site visit and writing the report take time, especially when the company has several sites.

What must a compliant audit contain?

A compliant audit is carried out by a qualified auditor, independent of the audited installations, following the NF EN 16247 standard. It is based on your actual consumption data, includes a site visit and leads to an analysis by use, then to costed recommendations with their investment, expected gain and payback.

Under the law, the companies concerned must also draw up an action plan based on these recommendations. The calculation methodology is set by the decree of 10 July 2025.

Audit, energy management system or tertiary decree: what is the difference?

The audit is a one-off diagnosis, renewed every four years. The energy management system (EMS), for example under ISO 50001, is a continuous approach that replaces the audit and becomes mandatory above 23.6 GWh. The tertiary decree is a separate obligation: it applies to tertiary buildings over 1,000 m², sets consumption-reduction targets and requires a declaration on the OPERAT platform.

The same site can combine an audit and the tertiary decree. The audit data then feed the decree's action plan, which avoids doing the same work twice.

Which grants can fund an audit?

Grants to fund an audit or energy diagnosis exist depending on company size, sector and region. They are offered by ADEME, by some regions and through schemes linked to energy savings certificates, and their conditions change from year to year.

Check them before ordering the audit: a grant is generally conditional on a prior application. The resulting action plan may then open the way to grants to fund the works.

How does Eneffic support you?

At Eneffic, we carry out energy audits and then follow the action plan with you, in line with your electricity contract. We start by checking whether your company is concerned, using your bills.