Online brand communities reflect a shared interest among participants that sustains community identity around and through brand consumption. While exchanges within such a community are typically supportive, conflict can exist between different, and sometimes competing, brand communities. The phenomena of communities in conflict introduces an element of ‘other’ that allows each community to delineate its values more succinctly by affording a comparative point of reference. The aim of this research is to understand online inter-community conflict using a boundary object theory lens to examine the how online brand communities construct and span boundaries. Using the example of two online brand communities comprising the followers of the authors J.K. Rowling and Terry Pratchett, preliminary results illuminate how discrete communities assert their individual boundary identity construction and spanning.