The rapid expansion of global e-commerce and digitally integrated logistics networks has intensified the need for scalable financial planning models capable of operating across high-growth, high-volatility environments. Traditional static budgeting and siloed forecasting approaches are increasingly inadequate for managing complex, multi-region operations characterized by fluctuating demand, variable fulfillment costs, and dynamic cross-border regulatory conditions. This study examines scalable financial planning models designed to support strategic, operational, and tactical decision-making in global e-commerce and logistics systems. This conceptualizes scalability in financial planning as the ability to maintain accuracy, responsiveness, and governance as transaction volumes, geographic reach, and service complexity expand. It explores modular and driver-based planning architectures that link revenue growth, customer acquisition, inventory dynamics, transportation costs, and last-mile delivery performance to financial outcomes. Particular emphasis is placed on integrated forecasting frameworks that combine real-time operational data, scenario modeling, and rolling forecasts to address demand uncertainty, capacity constraints, and supply chain disruptions. This further analyzes the role of advanced analytics, automation, and artificial intelligence in enabling continuous planning, rapid scenario evaluation, and proactive cost governance. These capabilities allow organizations to align financial plans with evolving logistics strategies, such as omni-channel fulfillment, regional warehousing optimization, and platform-based partnerships. In addition, the study highlights governance mechanisms, including standardized data models, control thresholds, and performance-linked incentives, that ensure scalability does not compromise financial discipline or risk management. By synthesizing insights from financial planning, supply chain management, and digital platform economics, this abstract demonstrates how scalable financial planning models enhance resilience, capital efficiency, and strategic agility in global e-commerce and logistics ecosystems. The findings have implications for executives, financial planners, and policymakers seeking to support sustainable growth in digitally enabled, logistics-intensive business models.