At the start of each financial year, the Government prepares and presents a national budget that sets out expected revenues and authorizes expenditure for ministries, departments, and statutory bodies. The approved budget reflects the Government’s best estimates at that time, but it is based on assumptions about economic conditions, project timelines, and operational needs.

A supplementary appropriation becomes necessary when circumstances change during the year and the existing budget is no longer sufficient or appropriate. This may occur due to unforeseen events (such as natural disasters or emergencies), higher-than-anticipated costs, new policy decisions, legal obligations, or revenue shortfalls that require adjustments to spending plans.