This Study examines how best to design guarantee products, in the context of Financial Instruments ("FI"), to meet current demand and market failure in urban development and regeneration projects. It seeks to demonstrate why the use of Financial Guarantees ("FG") can be, in certain contexts, more suitable to foster urban projects compared to other financial products including subsidised loans. The Study also defines the most appropriate FG structures, risk allocation, and performance indicators, and recommends a fund structure that could be set up by Managing Authorities ("MA") to offer FGs as a FI in JESSICA implementation.