The Act on Energy Efficiency of 2015 requires large enterprises - those having more than 250 employees, or an annual turnover over €50 million or an annual balance sheet total exceeding €43 million - to conduct an energy audit every four years. Large enterprises also must register with the Hungarian Energy and Public Utility Regulatory Authority (HEA) and report their energy consumption data to the HEA annually.

The purpose of the audits is to evaluate how the energy use of a site, office or plant can be optimized.

Property owners and lessees of more than 50% of a building or plant must comply with the annual reporting obligation. A large enterprise having an EN ISO 50001 certificate is exempted from the audit requirement, as are the members of its group of enterprises if said certificate states that it applies also to the group members. The certificate, however, must be filed with the HEA every four years.

The deadline for the first audit was December 5, 2015; the deadline for the registration with the HEA was January 20, 2016. If an enterprise fails to conduct the audit, the HEA will provide it with a 90 day deadline during which the enterprise may conduct the audit. If the enterprise fails to meet that deadline, the HEA may impose a fine of up to HUF 10 million on the enterprise. Because several enterprises have not yet complied with the audit obligations, the HEA, as a courtesy measure, will not impose audit obligation related fines until December 31, 2016. However, there is no indulgence for failure to meet the registration obligation: those enterprises who have not registered by January 20, 2016 may face a fine of up to HUF 1 million. Therefore, it is advisable to submit the registration form - available on the HEA's website - as soon as possible.