Mobile Device Adoption and Digital Financial Transformation in East Africa: Financial Inclusion, Institutional Risk, and Governance Challenges

East Africa has become one of the world’s most significant laboratories for mobile-enabled digital finance. Across Kenya, Uganda, and Tanzania, mobile phones have evolved from communication devices into the dominant access layer for payments, savings, remittances, merchant transactions, and digital credit. This paper examines how mobile device adoption has shaped digital financial transformation in East Africa and analyses the institutional, operational, and cyber risks that accompany this transformation. The study adopts a structured qualitative review of peer-reviewed literature, policy documents, industry reports, and recent regional datasets from GSMA, the World Bank, FinAccess Kenya, FinScope Uganda, FinScope Tanzania, and central-bank payment-system reports. The evidence shows that mobile devices have widened formal financial participation, reduced transaction frictions, and enabled financial deepening among low-income and previously excluded populations. At the same time, they have shifted important elements of financial risk to user-controlled endpoints and agent-mediated ecosystems through SIM-swap fraud, phishing, device insecurity, privacy leakages, and blurred liability between telecom operators, fintechs, and financial institutions. The paper argues that mobile-led financial transformation in East Africa should be understood as a socio-technical reconfiguration rather than a purely technological upgrade. Sustainable progress therefore depends not only on innovation and adoption, but also on stronger endpoint security, coordinated telecomfinance regulation, consumer protection, and regionally harmonised governance frameworks.