While an increasing body of literature progressively proposes that accounting–marketing integration would yield strategic marketing synergies, another stream of literature suggests ineffective accounting–marketing integration. This paper aims to bridge the dyadic research gap in the optimal business performance arising from the integration of accounting and marketing functions. Based on a survey of 162 responses (with 75 dyads) from accounting and marketing managers in UK financial services organisations, this study identifies departmental differences and boundary fencing as core relational features in this dyad. Despite the perceptual divergences in the accounting–marketing dyad, most respondents perceived an integration of these functions to be an effective tool in their respective organisations. This study illuminates the existence and influence of cultural diversity and boundary fencing behaviour in the accounting–marketing dyad with respect to impasse, accounting–marketing integration and performance. This study explains performance driven task connectivity integration between accounting and marketing.