How often should a budget be reviewed?

Detailed Explanation

Monthly for the numbers, and at each life change for the structure. The monthly review is short — compare actual against plan by category, and look for the categories that drift consistently rather than the ones that missed once. Consistent drift means the plan is wrong, not that the month was unusual. Structural review is triggered by events rather than the calendar: a change in income, housing, dependants or debt. Small adjustments applied regularly compound into stability; a full rebuild every six months usually means the plan was never realistic.