PurposeThis study aims to investigate how indigenous socio-cultural (ISC) practices within informal networks, such as guanxi and wasta, provide benefits beyond mere access. Specifically, the authors explore their global impact on B2B relationships, focusing on reciprocity. A multiregional sample extends research on ISC practices in B2B relationships by examining contingency effects of informal network ties.Design/methodology/approachThe authors surveyed 404 buyers in two developed (Hong Kong and Portugal) and two emerging economies (Kuwait and Colombia), and also categorized by strong and weak informal network ties. Using structural equation modeling, the authors examined a relationship marketing (RM) model from a typology (Clubs, Sociocracies, Clans and Compadres) for assessing contingency effects.FindingsThe study reveals that in developed economies with strong formal institutions, negative aspects of favor reciprocity norms intensify unless informal networks are driven by strict sociomoral obligations. This supports research indicating that contractual governance competes rather than complements relational governance. Moreover, trust-building processes are crucial in regions with low uncertainty tolerance to mitigate adverse effects.Practical implicationsSuppliers from developed nations need more than cultural communication insights when engaging in business in emerging markets. We acknowledge changes buyers may expect adherence to reciprocity rules embedded in the ISC practices of their informal networks.Originality/valueThis study pioneers a typology of social structures to analyze ISC practices across buyers with varying formal institutional strength and informal network ties. It sheds light on institutional dynamics, trust-building processes, and nuances surrounding both positive and negative aspects of reciprocity practices. Furthermore, it broadens the scope of RM to Asia, Europe, Latin America and the Middle East.