Zero-based budgeting UK: a worked example on a £30,000 salary

Before the month starts, you give every pound of your expected take-home pay a job, then you track spending against those jobs and move money between categories when life happens. The total of all categories must equal your income, no more and no less.

The difference from a looser plan such as the 50/30/20 rule is precision. With 50/30/20 you aim for rough percentages. With zero-based budgeting you decide that, say, £280 goes on food and £150 goes to your emergency fund, and any leftover pound is deliberately assigned rather than drifting into your current account balance.

Use the money that actually lands in your account, not your salary. For 2026/27, someone in England, Wales or Northern Ireland earning £30,000 pays about £3,486 in income tax (20% on earnings above the £12,570 Personal Allowance) and £1,394 in employee National Insurance (8% above £12,570). That leaves roughly £25,120 a year, or about £2,093 a month, before any pension contributions or student loan repayments.

Your figure will differ if you pay into a workplace pension, repay a student loan, live in Scotland or have a different tax code, so check your payslip or run your numbers through the take-home pay calculator. If your income varies month to month, budget using your lowest typical month and treat anything above it as extra to assign once it arrives.

Go through the last three months of bank and card statements and write down every payment. Then add the costs that do not appear monthly but always arrive eventually: car MOT and servicing, TV licence, birthdays, Christmas, glasses, annual subscriptions, school uniforms and holidays.

Divide each irregular cost by 12 and give it a monthly line. This is the step most people skip, and it is why a budget that looks balanced in March collapses in December. Our guide to sinking funds shows how to hold this money separately so it is there when the bill lands.

Here is one example for a single renter outside London on the take-home pay above. The figures are illustrative, not targets: your rent and bills will be different, but the principle that the total matches income is the same.

Notice that £430 a month (debt, emergency fund, sinking funds, holiday) is going towards future you. Zero-based budgeting makes that visible, which is why many people find they save more with it than with a vague intention to save whatever is left.

Overspending in one category is normal. The rule is that you cover it by moving money from another category, so the total stays at zero. If groceries run £30 over, take £30 from fun money or the holiday line and note why. Over a few months this shows you which numbers were unrealistic, and you adjust the plan rather than abandoning it.

Practical set-up that helps:

Irregular income. If you are self-employed or work variable hours, build the budget on your lowest typical month and keep a buffer of one month of spending in your current account. When a good month comes in, assign the extra in order: rebuild the buffer, then savings, then any goals. Our guide to budgeting on an irregular income covers this in detail.

Couples. Agree the shared bills first, decide how each person contributes (equal amounts or in proportion to income), then each person zero-budgets what remains.

Universal Credit. UC is paid monthly in arrears and can change from one assessment period to the next. Budget on the most recent award and update the plan as soon as a new statement arrives.

A spreadsheet or a notebook works fine. The budget planner lets you enter your income and categories and see the remainder update as you go, which is all a zero-based budget needs. For the savings lines, the emergency fund calculator helps you set a target and a timeframe.

If your savings line keeps getting raided, it can help to make saving a small daily action instead of one transfer. SYM is a free savings challenge app that tells you how much to put aside today and logs it with one tap, which pairs well with a zero-based plan that already has a savings job built in.