PurposeThe study aims to investigate cultural aspects in supply chains, analysing the effect that local customs may have in the quality of buyer–supplier relationships. Building on the premisses of social exchange theory (SET), it concentrates on the impacts that suppliers’ use of local practices and informal networks may have in buyers’ attitudes and perceptions. The issues addressed and the empirical evidence provided represent initial, yet important steps in the fulfilment of the ‘cultural void’ within supply chain social sustainability (SCCS) literature.Design/methodology/approachThrough a role-playing experiment applied to a total sample of 468 participants, the effects of Chinese guanxi, Russian blat, South Korean yongo and Brazilian jeitinho on buyers’ satisfaction, buyers’ commitment, trust and solution severity are measured by their use to access informal networks as solutions to both common (i.e. documentation irregularities) and extraordinary (i.e. modern slavery) supply chain problems.FindingsResults show that, while the activation of informal networks may impact buyers’ perceptions, the use of some local practices by suppliers (i.e. Chinese guanxi and Brazilian jeitinho) cause greater variations in buyers’ attitudes and perceptions than others (i.e. South Korean yongo and Russian blat), with ethical offences (i.e. modern slavery) and higher levels of buyers’ dependency acting as catalysts of these processes.Originality/valueThe investigation of cultural practices typical of economically peripheral countries contributes to the understanding of new facets of buyer–supplier relationships, with the investigation of non-Northwestern practices being particularly important in this regard.