The European Union has set a climate neutrality goal that requires all member countries to reduce their energy consumption. In 2021, businesses accounted for approximately one-quarter of the EU's energy consumption therefore, they play a significant role in its reduction. Hungary has taken steps to encourage companies to improve their energy efficiency, mandating large consumer companies to perform annual energy audits and publish their results. Our research focuses on the results of energy efficiency measures implemented by these large consumer companies. Based on online energy reports that were readily available, we analysed the energy performance of companies with more than 1,000 employees between 2017 and 2021. Data narrowing resulted in a sample of 24 companies that are not considered representative, but their analysis indicates that low-cost employee awareness-raising and lighting upgrades were the most used efficiency measures. Results show that energy savings resulting from lighting modernisation ranged from 11 to 844 GJ per year, while savings from cooling/heating modernisation ranged from 4,7 to 47,000 GJ per year. By modernising building systems such as ventilation, the studied companies achieved energy savings ranging from 10 to 403 GJ. The annual energy savings achieved through production modernisation ranged from 972 to 510,435 GJ. Due to the inconsistencies in the data, our analysis also highlighted the importance of stricter monitoring and establishing a database of energy consumption data from companies performing annual audits.