Do you have high energy consumption? From 2026, an energy audit may no longer be enough – ISO will be mandatory!
As of 1 January 2026, an amendment to Act No. 406/2000 Coll., on Energy Management, will come into force, fundamentally changing the rules for the obligation to conduct an energy audit and to implement an energy management system according to the ISO 50001 standard. Under the amended wording, the decisive factor will newly be the average annual final energy consumption over three consecutive calendar years. For this reason, it will be necessary from 1 January 2026 to monitor energy consumption and to evaluate it at the beginning of 2029 in connection with the obligations arising from the amended act.
The amendment abandons the existing limits based on the number of employees or the entrepreneur’s turnover. For this reason, it will be necessary on 1 January 2026 to evaluate energy consumption for the preceding years and to draw the appropriate conclusions in connection with the obligations arising from the amended wording of the Act.
When is an energy audit newly required, and when is it no longer sufficient?
Obligation to implement a certified energy management system
If the average annual final energy consumption of the energy management system over the last three years exceeds 23,611 MWh, an obligation arises to implement and certify an energy management system in accordance with ISO 50001, within 2 years from the moment the obligation arises, i.e. no later than 31 December 2027.
This obligation applies to business entities as well as public administration bodies and their established organizations.
Obligation to prepare an energy audit
With an average annual final energy consumption higher than 2,778 MWh (and at the same time lower than 23,611 MWh), it is necessary to ensure the preparation of an energy audit by a person holding the relevant authorization as an energy specialist.
This audit is valid for 4 years, or until a significant change in the energy management system is carried out (e.g. an increase in consumption of more than 25%).
This requirement applies across all sectors, i.e. regardless of whether the entity is a business or a public body.
For the public sector, an additional consumption band applies: if the average annual final energy consumption exceeds 500 MWh but does not exceed 2,778 MWh, an obligation arises to carry out an energy audit, the validity of which is 10 years.
When no obligation arises
In the cases listed below, it is not necessary to ensure an energy audit or to implement and certify an energy management system in accordance with ISO 50001.
- For public entities, the lower threshold of average annual final energy consumption is 500 MWh.
- For business entities, the threshold of average annual final energy consumption is set at 2,778 MWh.
Possibility to substitute the audit with certified EnMS according to ISO 50001
The legal obligation to carry out an energy audit can still alternatively be fulfilled by implementing and subsequently certifying an energy management system according to ISO 50001. The scope of this system corresponds to that of an energy audit, i.e., it must cover the entire energy economy.
Legal penalties for non-compliance
Failure to comply with legislative obligations is associated with fines specified in § 12a of the Act. For non-compliance with the above obligations, a legal entity — i.e., both a business entity and a representative of the public sector — may be fined up to CZK 5 million.
Transitional provisions – what if I already have an energy audit?
The amendment to the Act includes transitional provisions governing the validity of energy audits carried out before the amendment came into effect. For businesses with final consumption in the range of 2,778 – 23,611 MWh, the validity of an existing energy audit is limited to no more than 4 years from the date the amendment takes effect, i.e., until 31 December 2029.
For the public sector: if they have an energy audit prepared under the legislation in force before the amendment took effect and their final energy consumption is in the range of 2,778 – 23,611 MWh, the audit remains valid for no more than 4 years from the effective date of the amendment. If the entity’s final consumption is in the range of 500 – 2,778 MWh, the audit remains valid for 10 years from the date it was carried out.
What does this mean in practice?
- Turnover and number of employees no longer matter — the only key factor is the final annual energy consumption.
- The organisation’s energy consumption is assessed over the last three calendar years, not two as before.
- The threshold for the obligation to carry out an energy audit for businesses is reduced — from 5,000 MWh to 2,778 MWh.
- For public sector entities, an audit is mandatory from 500 MWh once every 10 years, and now from 2,778 MWh once every 4 years.
- Energy audits prepared before the amendment takes effect remain valid until the end of 2029, except for the public sector with consumption between 500 – 2,778 MWh, where validity remains 10 years from the date of preparation.
- The implementation of an energy management system in accordance with ISO 50001 is mandatory for consumption above 23,611 MWh.
- An energy audit can still be substituted by an established and certified energy management system.
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