UK Income Tax Explained: Bands, Rates, and Allowances
The UK income tax system runs on one simple principle: you only pay tax on income above a certain threshold, and different portions of your income are taxed at different rates. Whether you're salaried, self-employed, or running a business, understanding income tax explained through the bands and rates means you can plan better and spot opportunities to reduce what you owe. This guide breaks down the 2026 tax bands, shows you how the personal allowance works, and explains the mistakes that cost people hundreds of pounds a year.
How UK Income Tax Works
You don't pay income tax on your first £12,570 of earnings in the 2025/26 tax year — that's your personal allowance. Above that, tax is progressive: the next chunk of income is taxed at 20%, then 40%, then 45% at the very top. The word "progressive" is crucial here. A marginal tax rate of 40% doesn't mean you pay 40% on everything. It means you pay 40% only on the income within that band.
Take a concrete example: someone earning £60,000 a year in the UK. They pay:
- £0 on the first £12,570 (personal allowance)
- 20% on the next £37,700 (£12,571 to £50,270) = £7,540
- 40% on the remaining £9,730 (£50,271 to £60,000) = £3,892
- Total tax: £11,432, which is 19% of gross income, not 40%.
That's how marginal rates work. The band only applies to the income within it.
The Four UK Tax Bands (2025/26)
| Band | Income range | Rate |
|---|---|---|
| Personal allowance | £0–£12,570 | 0% |
| Basic rate | £12,571–£50,270 | 20% |
| Higher rate | £50,271–£125,140 | 40% |
| Additional rate | £125,141+ | 45% |
The personal allowance is the most important. It's the income you're allowed to earn tax-free every year, and it resets on 6 April (the start of the UK tax year, not 1 January). If you earn less than £12,570, you pay no income tax at all — though you may still owe National Insurance contributions, which is a separate levy entirely.
The basic rate is where most people sit. If you earn between £12,571 and £50,270, you're a basic rate taxpayer, and 20% of the income above your personal allowance is taxed at this rate.
The higher rate kicks in at £50,271. Higher rate taxpayers (earning £50,271–£125,140) pay 40% on income in this band. They still pay 20% on the basic rate band — the rates are marginal, not a flat rate on all income.
The additional rate applies above £125,141 and attracts 45% tax. Fewer than 2% of UK taxpayers hit this bracket. (And if you earn over £100,000, your personal allowance shrinks — you lose £1 of allowance for every £2 of income above £100,000, so it's gone completely at £125,140.)
Personal Allowance and Tax-Free Allowances
Your personal allowance is the biggest tax relief most people get, but it's not the only one worth knowing about.
Tax-Free Allowances include:
Marriage Allowance: If one partner earns less than the personal allowance and the other is a basic rate taxpayer, you can transfer up to £1,260 of unused allowance. That saves the higher earner £252 per year in tax (20% of £1,260). It takes 5 minutes to set up online and can be backdated 4 years — if you didn't claim before, you can claim now and get the refund.
Pension contributions: Money you pay into a pension gets tax relief at your marginal rate. If you earn £40,000 and contribute £100 per month from net pay into a pension, that £100 becomes £125 in your pension pot (you get 20% basic rate relief). If you're a higher rate taxpayer at £60,000, that same £100 contribution actually costs you only £60 after relief — that's a 40% gain from tax relief alone.
ISA allowance: An Individual Savings Account lets you save up to £20,000 per tax year completely tax-free on interest and gains. Stocks ISAs, Cash ISAs, and Lifetime ISAs all count toward this £20,000 total.
Personal Savings Allowance: Basic rate taxpayers can earn up to £1,000 in savings interest tax-free. Higher rate taxpayers get £500. Additional rate taxpayers get £0.
Tax Deductions and Relief You Shouldn't Miss
For employees: Most employees assume they can't claim expenses. You can. If you work from home permanently, you can claim £6 per week or £312 per year without needing receipts. Professional fees (accountant, engineering memberships), uniforms (if they're not ordinary everyday clothes — a nurse's uniform yes, business suit no), and professional development courses are all deductible.
For self-employed and business owners: Every pound of profit is taxable, but so is every pound of legitimate expense. Office supplies, equipment, mileage (45p per mile for cars), phone and internet costs (split business/personal), professional insurance, and training are all deductible. Keep digital records — bank statements and receipts in a folder are enough. HMRC expects you to keep records for 5 years, and they can enquire into your returns up to 4 years back.
Pension tax relief: When you contribute to a registered pension, you get 20% tax relief automatically. Higher rate taxpayers should claim the extra 20% relief on their tax return. Someone earning £50,000 contributing £10,000 per year:
- They contribute £10,000 from their bank account
- HMRC adds £2,500 (20% relief)
- Their pension grows with £12,500 invested
- That pension pot grows tax-free inside the pension wrapper
This is compounding working in your favour before you even earn the investment returns.
Common Tax Mistakes That Cost Real Money
Overpaying on PAYE. Your tax code (on your payslip, usually 1257L) tells your employer how much personal allowance you get. If it's wrong, you overpay or underpay every month. Wrong codes often appear after job changes or benefits. Check your code every payslip.
Not claiming Marriage Allowance. If you're married and one earns less than £12,570 while the other earns £12,571–£50,270, you're leaving £252 per year on the table.
Forgetting pension relief as a higher rate taxpayer. Higher rate taxpayers get an extra 20% relief on pension contributions, but only if they claim it on their Self Assessment tax return. Many higher earners forget this.
Missing self-employed registration deadlines. If you're self-employed, you must register with HMRC within 3 months of starting. Missing this triggers penalties. Set a reminder for the month you start trading.
Ignoring Limited Company vs Sole Trader tax treatment. The wrong business structure costs thousands in unnecessary tax. A director taking salary plus dividends can often pay less income tax and National Insurance than a sole trader earning the same profit.
Frequently Asked Questions
Q: What's the difference between income tax and National Insurance? A: They're separate taxes with different rules. Income tax is based on your income band; National Insurance contributions are based on your earnings above £12,570. Both are deducted from your pay. At a £40,000 salary, you'll pay roughly £5,700 income tax and £3,300 National Insurance combined.
Q: Can I claim tax relief on a pension contribution if I'm unemployed? A: Yes, if you have any earnings at all (self-employed income, part-time work, etc.). You can contribute up to £3,600 per year without earnings, and HMRC gives you 20% relief automatically (so £3,600 becomes £4,500 in your pension).
Q: What counts as "income" for tax purposes? A: Salary and self-employed profits are the main ones. But also: rental income, dividend income (if you own shares), and unearned income (interest, capital gains above the allowance). Most have separate allowances.
Q: I'm self-employed and earned £45,000 last year. How much income tax will I owe? A: Roughly £6,485 in income tax (£45,000 − £12,570 personal allowance = £32,430 × 20%). You'll also owe National Insurance contributions and may need to file a Self Assessment tax return by 31 January.
Q: What if I go over the £20,000 ISA allowance in a year? A: You can't. The ISA provider will block additional deposits once you hit £20,000 in that tax year. You have to wait until 6 April (the next tax year) to deposit more.
Q: Are bonuses taxed differently from salary? A: No, they're ordinary income and taxed at your marginal rate. If you earn £50,000 salary and get a £10,000 bonus, you pay 40% income tax on that bonus (because it falls in the higher rate band).
Q: Can I carry forward unused personal allowance to next year? A: No, it's use-it-or-lose-it. If you earn £10,000 in a year, the remaining £2,570 of allowance is gone. This is why Marriage Allowance exists — to let couples use each other's unused allowance.
Q: How does Capital Gains Tax fit in with income tax? A: Separately. You pay income tax on earnings, salaries, and profits. Capital gains tax applies to profits from selling investments, property (with some exceptions), or assets. The first £3,000 of gains per year are tax-free, then you pay 20% (basic rate) or 40% (higher rate).
What to Do Next
Now that you understand how income tax bands and rates work, calculate what you actually owe. Use our salary calculator (linked to /salary) to apply the correct tax bands to your income and see your take-home pay. If you're self-employed or running a Limited Company, you'll file a Self Assessment tax return by 31 January to settle your tax bill.
If you think you've been overpaying, check your HMRC online account and verify your tax code. Keep records of any expenses or changes in circumstances — they're your evidence if HMRC ever asks questions.