Purpose This paper aims to test a contingency-based path model that concurrently links the role of management accountants (MA) and advanced manufacturing technologies (AMTs) to cost system sophistication (CSS), as well as linking the latter to improvements in organisational performance through improving cost management and product planning decisions. Design/methodology/approach This paper used the questionnaire survey strategy to collect data from 373 medium and large manufacturing business units based in the UK, then subjected the data to structural equation modelling analysis to test a contingency-based path model. Findings The results show that the role of MAs and AMTs positively influence CSS. Moreover, it was found that the latter is positively associated with improvements in cost management decisions which, in turn, lead to improvements in organisational performance. However, no support was found for the association between the level of CSS and improvements in product planning decisions, although the latter was found to be positively associated with organisational performance. These results confirm the theory and empirical findings regarding the role that MAs and AMTs play in designing the cost accounting system, and support the argument that adopting sophisticated cost systems does not lead directly to improvements in organisational performance, unless the benefits of such systems, in terms of improved decision-making and cost applications, are used. Originality/value This research contributes to the literature by testing a contingency-based path model that incorporates hitherto underexamined contextual factors, namely, the role of MAs and AMTs; examining the effect of CSS on a critical output, organisational performance and the mechanisms of this effect; and considering the complexity of the business environments through the concurrent testing of the relationships involved in the research model.