Despite recognizing the importance of external dynamics to employee organizational identification, this factor is under explored in today's evermore interdependent organizations. We theorize how organizational identification can be influenced by an employer's horizontal partnerships with entities such as sport teams or charities. Drawing on insights from the organizational identification and marketing literatures, we explore how events concerning an organization's horizontal partner become salient to employees, how they evaluate the implications of the partnership, and how their identification may shift as a result. Surprisingly, our model reveals that partnerships that have low congruence may lead to significant positive identification shifts for some individuals; while partnerships that are seemingly positive for an organization may result in negative identification shifts. Our theorizing makes two important contributions. First, it introduces the potential of horizontal relationships with other organizations to shape the important work relationship of identification with the focal employing organization. Second, it outlines the processes through which horizontal partners can make a difference in work relationships and sets the stage to better understand how they can strengthen and hinder these relationships, as well as encroach on non-work life.