This article investigates the birth and evolution of a Business Improvement District (BID) in Talimhane, Istanbul, which is the first case of use of this instrument of neoliberal governance in the Turkish city. The distinctive nature of the Talimhane BID consists in the fact that it has been developed through a series of informal and piecemeal arrangements. The article first reviews the evolution, characteristics, and critical aspects of BIDs. It then focuses on the case study of this “informal BID” in Talimhane, analysing its origins, features, and outcomes. The informal nature of this BID is stressed as a key factor in understanding its features and outcomes, and it emerges as a fundamental component of urban neoliberalism in Turkey: it allows a centralized and authoritarian government to maintain complete control over public space and private actors and activities, while promoting a process of devolving powers in favour of the private sector.