Interorganizational boundary spanning between multinational enterprises requires substantive internal “lateral collaboration” and “lateral alignment.” However, how actors coordinate laterally between multiple nodes and across multiple boundaries for interorganizational boundary spanning is unclear. This qualitative study of a large multinational demonstrates how actors collectively build and maintain interorganizational relationships through collective boundary spanning. To coordinate this activity, actors strategize and map contributors for collective action and then synchronize their communication and problem-solving to ensure lateral collaboration and alignment. This article contributes to the extant literature by a providing a framework depicting how boundary-spanning coordination leads to lateral collaboration and lateral