A decade after Sathosi Nakamoto published his famous whitepaper, blockchain technology (BT) has started to become widely recognized and used beyond the cryptocurrency Bitcoin. While the financial sector is the most prominent adopter of the technology, numerous other fields of application for the ground-breaking innovation are discussed by researchers and practitioners alike. One key area in which blockchain-based applications are expected to drive radical and disruptive innovation is smart cities. BT provides unique benefits which smart cities can leverage to improve quality of life, adminis-trative processes, and environmental sustainability. However, due to the entrepreneurial dynamics and abundant fields of application for BT in smart cities, an integrated and boundary-spanning analysis is lacking. Thus, our paper aims at analysing how BT is used in different smart city business models to present a multi-layer taxonomy. For this purpose, we identified a global sample of 80 startups which offer products or services for smart cities and examined their business models. The paper explores economic and technological characteristics of blockchain based smart city applications. These unique insights will be useful for researchers, practitioners, and regulators.