Mandatory energy audit in 2026: thresholds, deadlines and ISO 50001

In Italy today, an energy audit is mandatory every four years for large companies and energy-intensive companies, under Legislative Decree 102/2014. Directive (EU) 2023/1791 shifts the criterion to consumption: an audit for those exceeding an average of 10 TJ a year and a certified energy management system above 85 TJ, regardless of company size. As of October 2026 the Italian transposition decree has not yet been published in the Official Gazette, but the European dates are already set and now is the time to check where your company stands.

What changes for energy audits in 2026

An energy audit (diagnosi energetica in Italian) is a structured analysis of a company’s consumption: where energy is used, how much is wasted and which measures are worth taking, with estimated savings and costs. In Italy it has been mandatory since 2015 for certain categories of companies, which submit it to ENEA, the national energy agency.

The change comes from the EED, Directive (EU) 2023/1791, the recast of the European energy efficiency directive. Article 11 changes the logic of the obligation: what matters is no longer whether you are a large company, but how much energy you consume. This means SMEs with energy-intensive processes may also fall within scope, while a large service company with low consumption could fall out of it.

The directive was due to be transposed by 11 October 2025. Italy has not yet completed transposition: a draft legislative decree has circulated, which is expected to replace Legislative Decree 102/2014, and on 1 October 2026 the European Commission sent Italy a reasoned opinion for incomplete transposition. Until the decree is published, the rules in force remain those of Legislative Decree 102/2014.

Who is obliged today: the rules of Legislative Decree 102/2014

Article 8 of Legislative Decree 102/2014 requires an audit from two categories:

• large companies, i.e. those with at least 250 employees and annual turnover above 50 million euros or a balance sheet total above 43 million euros;
• energy-intensive companies, registered in the list managed by CSEA.

The audit must be repeated every four years, with a deadline of 5 December, and uploaded to ENEA’s Audit102 portal. It must be carried out by certified parties: Energy Management Experts (EGE) under UNI CEI 11339, ESCOs under UNI CEI 11352 or certified energy auditors. Large companies with total consumption below 50 toe a year are exempt, but must still submit a self-declaration on the portal.

The penalties under Article 16 range from 4,000 to 40,000 euros for an audit not carried out and from 2,000 to 20,000 euros for a non-compliant audit. Paying the penalty does not remove the obligation to carry out the audit.

The new consumption-based thresholds

The directive sets two thresholds, calculated on average annual energy consumption over the previous three years, taking into account all energy carriers: electricity, natural gas, diesel, LPG, fuels and so on.

The conversions are indicative: 1 TJ corresponds to about 277.8 MWh and about 23.9 toe. For natural gas, the equivalent in cubic metres depends on the calorific value shown on the bill.

Those who already carry out periodic audits continue to do so at least every four years. According to industry analyses, the drafts of the Italian decree circulated so far confirm the European thresholds and the 11 October 2026 deadline; the final text could, however, change important details, such as the timeframes for compliance and the content to be submitted to ENEA.

How to check whether you exceed the threshold

The calculation is simple if your data is in order. You need actual consumption for the last three years, site by site.

1. Gather the electricity and gas bills and the invoices for diesel, LPG and fuel for all sites and company vehicles, for the last three years.
2. Convert each consumption figure into a common unit (GJ or toe), using the calorific value of the fuels.
3. Add up the energy carriers for each year and calculate the three-year average.
4. Compare the average with the thresholds of 10 TJ (equal to 10,000 GJ) and 85 TJ.
5. Keep the calculation and the data sources: you will need them both for the audit and for any inspections.

An example: a manufacturing company that consumes an average of 1.8 GWh of electricity and 150,000 Sm³ of gas a year reaches about 6.5 TJ for electricity and about 5.2 TJ for gas, i.e. more than 11 TJ in total. Even though it is an SME, under the new rule it would fall within the audit obligation.

This is the same data you need for Scope 1 and Scope 2 emissions. With Envify you can upload the bills for all your sites as they are and get consumption and emissions organised by year; the calculation method is explained step by step in the guide to calculating emissions from a utility bill.

Deadlines, ENEA and penalties: what to know now

As of October 2026, the picture has two parallel tracks that are worth keeping separate:

• If you are already obliged under Legislative Decree 102/2014, you continue to follow the four-year cycle with a 5 December deadline. Check the date of your last audit: if you carried it out in 2023, your next deadline is December 2027.
• If you fall within scope only under the new thresholds, the directive sets the first audit by 11 October 2026. A directive that has not been transposed does not, as a rule, create obligations that can be directly enforced with penalties against companies: penalties will come with the Italian decree. The deadline nonetheless remains the European reference point, and transposition is under pressure from the infringement procedure.

In both cases ENEA remains the point of reference: it collects audits through the Audit102 portal, publishes operational and sector guidelines and carries out inspections. An audit generally takes a few months between data collection, on-site measurements and the final report, so waiting for the decree to get started means risking being late.

Audit or ISO 50001: which route makes sense

Below 85 TJ you can choose: carry out an audit every four years or adopt an energy management system, which exempts you from the audit. Above 85 TJ the certified system becomes mandatory. The directive also provides two other exemptions:

• companies with a certified environmental management system, such as ISO 14001 or EMAS, if the system includes an energy audit meeting the minimum criteria of Annex VI;
• companies with an energy performance contract that includes the elements of an energy management system.

ISO 50001 requires more work at the start (energy policy, indicators, targets, internal audits), but turns a periodic obligation into a continuous process. It makes most sense when consumption is close to 85 TJ, when you already have an ISO 14001 or ISO 9001 system to link it to, or when clients and banks ask you for energy data every year.

After the audit: action plan and transparency

This is where the most concrete difference from the past lies. Under the EED the audit is not enough: the company must draw up a concrete and feasible action plan that turns every technically or economically feasible recommendation into a measure, and present it to the management board. The plan and the rate of implementation of the recommendations must be published in the annual report, with due regard for commercial confidentiality.

The directive also requires the audit to be based on measured, traceable data and, where possible, on life cycle cost analysis rather than simple payback time. In practice the action plan closely resembles an emission reduction plan: the same measures and the same data, seen from an energy perspective. To choose where to start, you can look at the decarbonisation measures with the best return for SMEs.

Managing the audit, action plan and ESG reporting together avoids collecting the same numbers three times and makes the results more credible to clients, banks and inspectors.

Frequently asked questions