PurposeDelving into family business heterogeneity, this study applies fuzzy-set qualitative comparative analyses (fsQCA) to explain overlooked differences in the international performance of born global family firms (BGFFs) and non-born global family firms (n-BGFFs); through the lens of assemblage theory of family business internationalization, the study develops distinctive configurations of international entrepreneurial culture (IEC) for BGFFs and n-BGFFs.Design/methodology/approachThis study compares the theoretical tenets of IEC among 167 BGFFs versus 192 n-BGFFs in Malaysia using fsQCA – a configurational method. The study further deploys necessity analysis of fsQCA (NCA) to determine the necessity conditions within the identified configurations.FindingsBGFFs manifest elevated levels of international entrepreneurial orientation, international motivation and international non-competitor network orientation. In contrast, n-BGFFs rely on international markets, learning and competitor network orientations to secure international performance. Furthermore, necessary condition analysis (NCA) reveals that international entrepreneurial orientation and international motivation are the necessity conditions for BGFFs. In contrast, international market, learning and competitor network orientation are all required for n-BGFFs’ international performance.Originality/valueThis study is timely and contributes to advancing the international business theory of family firm internationalization. It also offers better theorizing for family firms’ heterogeneity, locating the source of that heterogeneity not just in the speed of internationalization but also in the composition of their different IECs.