It is widely assumed that political parties need to have members in order to fulfil their functions in a representative democracy (drawing up platforms, candidate nomination and electoral mobilization) and in terms of their legitimacy. However, the theoretical literature on party models – the evolution from the mass party to the catch-all party, the electoral-professional party and/or the cartel party – suggests an increasing marginalization of members within the party organization. In the business-firm party model, members no longer have any role whatsoever. The next phase in this development seems to be a party without members. This article analyses the contextual (societal, communicational and institutional) factors favouring the rise and endurance of the memberless party as well as the strategic conditions for doing without formal membership (such as maximizing the centralization of internal decision-making, promoting party unity and enhancing electoral effectiveness). The functioning of two no-member parties – the Freedom Party in the Netherlands and the Lega dei Ticinesi in Switzerland – will be discussed in the empirical part of this article.