Zero-based budgeting means giving every pound of your expected household income a job, such as bills, food, savings, debt repayments or spending, so your planned income minus outgoings equals zero. Start by listing your monthly income and regular costs, then estimate flexible spending and set aside money for irregular expenses such as car repairs or annual insurance. Use a household budget planner to compare your plan with actual spending and adjust it during the month if costs change. Keep a small buffer where possible, and review the budget regularly rather than treating it as a fixed rule.