The volatility in the price of gas and electricity on commodity markets led to the proclamation of the Temporary Crisis Framework for State Aid Measures by the EU in 2022. As of June of 2024, each EU member state is bound to implement a supplier-of-last-resort regime within the electricity market. This approach has been adopted by the Czech Republic, prior to the energy crisis. In an unprecedented move, the Czech government has implemented several regulatory interventions, including the enactment of an Extraordinary Market Situation for the entirety of 2023. The study’s primary objective is to analyze the impact of the interventions on the performance of these structurally important suppliers in the broader context of prior market developments. Suppliers were compelled by the law to supply consumers at fixed prices during 2023, and were therefore entitled to compensation, while being subject to a newly introduced tax surcharge on unanticipated profits. This arguably resulted in a novel approach from the perspective of regulatory economics, as unbundled suppliers do not possess a natural monopoly on a liberalized market. This study further delineates the evolving regulatory framework and the pertinent amendments to legislation and government decrees that impacted the regulation of the domestic energy market and evaluates their anticipated costs with data disclosed.