Civil law presumes that an entrepreneur acts as a professional, while the rules protecting electricity customers rely largely on disclosure. Drawing on behavioural economics, the article argues that both assumptions fail with respect to microentrepreneurs. It evaluates statutory classification (Germany), a default rule with standardised bills (Italy), and disclosure with ex post qualification (Poland). A CATI survey of 602 customers of one supplier (402 households, 200 businesses) shows that information on switching and on the comparison tool belongs to the least-read layer of the bill, that age and financial situation are associated with self-assessed knowledge but not the perceived comprehensibility of the bill, and that microentrepreneurs do not report understanding the bill better than households. The article formulates de lege lata conclusions concerning Annex I to Directive 2019/944, Article 31g of the Polish Energy Law, and Article 385⁵ of the Polish Civil Code, and de lege ferenda proposals favouring protection that does not depend on the addressee’s own initiative.