<p>The proclaimed goal of European energy policies is a just and sustainable energy transition. While extensive research has focused on energy transition and efficiency, micro-enterprises, a critical segment of the European economy, remain underexplored. Micro-enterprises account for 93.7% of EU companies and nearly 17% of total EU turnover. They are also a contributing factor to welfare, where entire families rely on the stability of a single micro-enterprise. Due to their size and supply chain positioning, they are disproportionately vulnerable to energy price fluctuations, supply disruptions and regulatory changes. We investigate the energy vulnerability of micro-enterprises in the EU, highlighting their unique challenges in energy transition policies, financial constraints, and market dynamics. A composite vulnerability index (MEVI) is developed, integrating factors like energy dependency, market access and business vulnerabilities, to rank EU Member States based on their micro-enterprise energy vulnerability. The findings suggest variations in vulnerability across countries, influenced by energy market structure, macroeconomic conditions or sector-specific energy needs. The research underscores the necessity for tailored policies and further data collection to better address the energy vulnerability of micro-enterprises, a sector often overlooked in energy policies.</p>