A monthly budget is the foundation of good money management. Whether you are trying to clear debt, save for a house deposit, or simply understand where your money is going, this guide walks you through every step of building a realistic UK budget.
For more budgeting tools and guides, see the Budgeting Hub.
Step 1: Calculate your monthly take-home income
Start with what arrives in your bank account each month — not your gross salary.
Include:
- Net salary (after tax, NI, pension contributions)
- Benefits (Universal Credit, Child Benefit, Tax Credits, DLA/PIP)
- Self-employment income (monthly average)
- Rental income (after expenses)
- Child maintenance received
- Any other regular income
Exclude:
- Irregular overtime or bonuses (add these to savings when received)
- Tax refunds (one-off)
- Gifts
Use a three-month average if your income varies.
Step 2: List all your expenses
Divide your spending into fixed and variable categories:
Fixed expenses (the same every month)
| Category | Examples |
|---|---|
| Housing | Rent or mortgage, service charge, ground rent |
| Council Tax | Usually divided into 10 monthly payments |
| Energy | Gas and electricity direct debit |
| Water | Water rates |
| Internet and phone | Broadband, mobile phone contract |
| Insurance | Contents, life, car, health |
| Loan repayments | Personal loans, car finance, student loan (Plan 1/2 threshold) |
| Minimum debt payments | Credit card minimums, overdraft fees |
| Subscriptions | Streaming services, gym membership |
| Pension (if not via payroll) | SIPP or personal pension contributions |
Variable expenses (change month to month)
| Category | Examples |
|---|---|
| Groceries | Food, household cleaning products |
| Eating out and takeaways | Restaurants, coffee shops, Just Eat |
| Transport | Petrol, train tickets, bus fares, parking |
| Clothing | Everyday clothing, workwear |
| Personal care | Haircuts, toiletries |
| Children | School trips, clubs, uniform |
| Health | Prescriptions, dentist, optician |
| Entertainment | Cinema, events, hobbies |
| Gifts | Birthdays, Christmas |
Irregular/sinking fund expenses (annual costs, divided monthly)
| Expense | Typical annual cost | Monthly saving |
|---|---|---|
| Car insurance | £600–£1,200 | £50–£100 |
| Car MOT and servicing | £300–£500 | £25–£42 |
| Home insurance | £150–£400 | £13–£33 |
| Christmas gifts | £300–£800 | £25–£67 |
| Annual holiday | £500–£3,000 | £42–£250 |
| TV Licence | £174.50 | £14.54 |
| Dentist | £100–£300 | £8–£25 |
Step 3: Apply the 50/30/20 framework
The 50/30/20 rule is a simple way to check whether your budget is balanced:
| Category | Target % | Examples |
|---|---|---|
| Needs | 50% | Rent/mortgage, bills, food, transport, minimum debt payments |
| Wants | 30% | Dining out, subscriptions, hobbies, holidays |
| Savings + debt repayment | 20% | Emergency fund, savings goals, overpaying debts |
Example: £2,500/month take-home pay
| Category | Target | Amount |
|---|---|---|
| Needs (50%) | £1,250 | Housing + bills + food + transport |
| Wants (30%) | £750 | Leisure, eating out, subscriptions |
| Savings (20%) | £500 | Emergency fund, house deposit, ISA |
Adjust as needed: In expensive cities like London, housing alone may be 40–50% of income. In this case, reduce the wants percentage rather than the savings percentage — protect savings first.
Step 4: Identify your surplus or deficit
Monthly surplus/deficit = Total income − Total expenses
If you have a surplus: direct it to your savings priority (emergency fund → debt → goals).
If you have a deficit: work through expenses from largest to smallest and look for cuts. Common areas to reduce:
- Subscriptions you do not use actively (average UK household has £1,000+ in unused subscriptions per year)
- Eating out and takeaways (the highest-discretionary category for most households)
- Energy — switch tariff, reduce usage (see Energy Cost Hub)
- Insurance — compare and switch at renewal
Step 5: Set up the system
A budget only works if you can maintain it. Choose a system that fits your habits:
The envelope method (cash budgeting)
Withdraw cash for each variable category at the start of the month. When the envelope is empty, spending for that category stops. Works well for impulse spenders.
Separate bank accounts
Open a second current account or savings pot for each budget category. Transfer the allocated amount on payday. Many UK banks (Monzo, Starling, Chase) offer free savings pots or spaces.
Automated savings
Set up a standing order on payday to move savings to a separate account before you can spend them. The “pay yourself first” method is the most reliable way to make savings consistent.
Fortnightly check-ins
Review your budget every fortnight — not just month-end. Catching overspending two weeks in gives you time to course-correct. Most banking apps show categorised spending in real time.
Common UK budgeting mistakes
- Forgetting annual expenses — car insurance, Christmas, and holidays create predictable cash crunches if not planned for with sinking funds
- Budgeting from gross income — always use take-home (net) pay
- Setting unrealistic targets — a budget 10% below actual spending is more sustainable than one 40% below
- Not reviewing after life changes — salary increases, relationship changes, new subscriptions, rent renewals all need to trigger a budget review
- Ignoring minimum debt payments — these are fixed expenses; only the amount above the minimum belongs in the “savings + debt” category