Digital Transformation (DT) is crucial for business internationalisation (BI), particularly in emerging economies. This study examines how business planning (BP) facilitates DT implementation, using Tunisia as a case study. It explores BP's role in sustaining DT across digital maturity stages and identifies factors contributing to digital business failures. Analysing data from 220 firms, the study employs survival analysis, using the Kaplan-Meier estimator and Cox proportional hazard regression, to assess how BP affects DT longevity. Findings highlight BP as a key enabler of DT and internationalisation, particularly post-COVID. The research offers theoretical and empirical insights into the intersection of BP, DT, and BI. It underscores the need for infrastructure improvements, e-administration, and enhanced internet quality to support DT in emerging markets. These insights provide valuable guidance for policymakers and business leaders aiming to leverage digital tools for sustainable growth and global competitiveness.