External legitimacy (EL) is a social mechanism relevant for organizational survival and growth. In order to enhance EL, recent studies propose to engage in partnerships (Dacin et al., 2007). A construct specifically developed for legitimacy in alliances is interpartner legitimacy (IPL) which refers to the mutual acknowledgement by partners that their action are proper (Kumar & Das, 2007). IPL affects alliance’s performance in fostering the cooperative milieu to best realize synergies. Despite the increase in alliances, scholarship has only recently paid attention to their legitimating function. Today, there is a greater sensitivity to possible influences of IPL on EL and a growing interest in identifying the role additional effects like resource transfer play in that context. Responding to this interest, we develop hypotheses stating that IPL affects the resources transferred in a partnership and both, in turn, enhance each partner’s EL.