This paper explores how a balanced scorecard (BSC) has been successfully implemented and institutionalised in a leading telecommunications company in Sri Lanka (Telinotec) through improvements over two phases (pre 2012 and post 2012). It adopts a qualitative methodology and case study approach and is founded upon the theoretical underpinnings of institutional theory, more specifically the institutionalisation model of Tolbert and Zucker (1996). The findings suggest that while the BSC was implemented in 2000, improvements via linking it to individual performance and the corporate strategy were done after 2012. This paper contributes to literature by illuminating how the BSC was initiated (habitualisation), translated into practice (objectification) and institutionalised (sedimentation) in a firm and offers insights to practitioners on making management accounting tools successful by continuously modifying to match managers' expectations and the context of the firm.