Zero-based budgeting (ZBB) is a budgeting method where all expenses must be justified for each new period, starting from a zero base, rather than basing the budget on previous spending levels. In ZBB, all expenses must be reviewed and approved, regardless of whether they are fixed or variable, ensuring that resources are allocated efficiently and strategically to support organizational priorities and objectives. ZBB requires departments and managers to justify all costs and expenditures based on their necessity, relevance, and potential contribution to achieving desired outcomes, promoting accountability, cost consciousness, and resource optimization throughout the organization. Unlike traditional budgeting methods that may inflate budgets based on historical spending patterns or incremental adjustments, ZBB encourages a more rigorous and systematic approach to budgeting, fostering greater transparency, scrutiny, and prioritization of spending decisions. By forcing managers to justify every expense from the ground up, ZBB can uncover inefficiencies, eliminate waste, and redirect resources to high-priority initiatives, driving cost savings, operational improvements, and organizational effectiveness.