The modern view of interdependent supply chain relationships is that of an integrative, collaborative system of information sharing whereby both the supplier and customer reap net benefits from the relationship (Kalwani and Narayandas [1995]; Kumar [1996]; Kinney and Wempe [2002]; Vickery et al. [2003]; Arend and Wisner [2005]). Recent research provides support for this modern view; Patatoukas [2012] finds that suppliers with high customer sales concentration achieve higher accounting rates of return. However, to reap the potential benefits of these relationships the parties need the ability to reliably contract with each other. The role of internal control quality on the ability to contract is an open empirical question. We examine the consequences of weak internal control environments for ongoing relationships by investigating the impact of supplier ICWs on the duration of supply chain relationships.