The increasing density and entanglement of international law and institutions leads to a growing potential for collisions between norms and rules emanating from different international institutions. It is an open question, however, when actors actually create manifest conflicts about overlapping norms and rules and how – and with what consequences – such conflicts are handled. We therefore utilize the concept of “interface conflicts” (ICs) in which two or more actors express positional differences over the scope or prevalence of different international norms. Building on the findings of the DFG research group OSAIC, we introduce the Interface Conflicts 1.0 dataset, which assembles information on 78 ICs. The dataset provides information on the actors and norms at stake in ICs and focuses specifically on their subsequent handling. It distinguishes co-operative from non-cooperative conflict management and codes the institutional as well as distributional outcomes of all management efforts. For changes from version 1.0 to version 2.0 see Change_log_Interface_Conflicts_2_0.pdf.