This guide outlines the principles and practices of zero-based budgeting (ZBB) in a marketing context. It emphasizes the necessity for a strategic approach to budgeting, where every expense must justify its relevance and contribution to current goals. The document discusses the importance of aligning budgets with business objectives rather than relying on previous years' expenditures. It highlights the challenges associated with implementing ZBB, particularly the complexities of managing numerous spreadsheets and ensuring accurate data inputs across teams. The guide stresses that ZBB requires a meticulous tracking of investments to substantiate returns, moving away from vague budgeting practices. It also notes that modern tools can streamline the ZBB process, making it more efficient and less burdensome for finance teams. By leveraging data and aligning spending with strategic priorities, organizations can enhance their financial planning and decision-making processes.