As the fiscal year begins on April 1, the budget is presented to the Diet at the beginning of the ordinary session convoked in January. The budget bill can only be initiated by the Cabinet. It is introduced first into the House of Representatives.When the budget is referred to the Budget Committee, that body may request the presence of the prime minister and other ministers of state and question them on the national administration in general. The budget proceedings frequently provide opportunities for criticizing the administration.
For a motion of amendment to the budget to be placed on the order of the day in a plenary sitting it must be supported by at least 50 members of the House of Representatives or at least 20 members of the House of Councillors.
After consideration of the budget, if the House of Councillors reaches a decision different from that of the House of Representatives, and if no compromise agreement can be reached by a conference committee of both houses, the decision of the House of Representatives prevails; in the case where the House of Councillors fails to take final action within 30 days (time in recess not included) of receipt of the budget passed by the House of Representatives, then that budget becomes the official national budget.