Business improvement districts (BIDs) are increasingly being advanced in a range of national contexts as a new delivery mechanism for securing improvement, regeneration and enhanced service delivery in specifically delineated districts. This paper considers BIDs as an example of a modern institutional design that is reconfiguring existing economic and legal regimes within town centres. Drawing on the theories of new institutional economics and transaction costs, the paper discusses how the contractual turn in urban governance advances our conceptual understanding of the rationale, scope and significance of partnership working. The discussion brings together emerging literatures around new ways of understanding partnership working in government thinking. It contrasts the advocacy and use of BIDs with the (previously established) practices of town centre management. It asserts that BIDs represent a new form of formalized and contractualized partnership working in sub-municipal governance, which has particular spatio-temporal implications for state-market-civil relations.