Abstract Business actors play increasingly important roles in global governance and international regulation. This paper considers how regime complexity influences the roles of businesses and impacts opportunities for business influence on international regulatory regimes. We conducted a scoping literature review of 243 articles from the International Regime Complexity (IRC) theory literature to explore if and how complexity affects the roles of businesses and their influence on international regulation. We found that complexity presents opportunities for businesses to regime shift and exploit knowledge asymmetry in order to influence international regulation. Further, IRC theory illustrates how the roles of businesses interact and leverage one another in order to create better opportunities for influence in specific international regulatory regimes. This paper contributes to IRC theory by building on the existing non-state actor discussions and offering specific theorization of business behavior, thus starting to bridge the gap between the empirical and theoretical understanding. Second, it contributes to existing discussions in business and politics literature by developing existing knowledge on the roles of businesses in global governance to better reflect the added dimension of complexity.