What Is Income Tax? A Plain-English UK Guide
Most people pay income tax every month without ever being shown how it actually works.
Understanding what is income tax in the UK — what you owe, what is free from tax, and where your money goes — can make a meaningful difference to how much you pay.
Income tax is the primary way HMRC collects revenue from individuals, and it applies to most forms of earnings — whether you are employed, self employed, or receiving a pension.
Knowing the basics of income tax means you are better placed to spot errors in your tax code, identify overpayments, and make use of the allowances available to you.
This income tax explained UK guide sets out the key facts so you can be confident you are paying the right amount.
How does income tax work in the UK?
Income tax is a charge on the money you earn above a certain threshold.
HMRC collects it on behalf of the government, using the revenue to fund public services: healthcare, education, and infrastructure.
The amount you pay depends on how much you earn and which tax band your income falls into.
Different portions of your income are taxed at different rates — earning more does not mean all of your income moves to a higher rate.
How income tax is collected depends on how you earn:
- If you are employed, tax is deducted automatically through the PAYE (Pay As You Earn) system. Your employer calculates the correct amount and sends it to HMRC each month on your behalf.
- If you are self employed, tax is not deducted at source. You report your earnings and calculate your own liability through a Self Assessment return submitted to HMRC each year or quarterly statements through making tax digital.
Both routes lead to the same outcome: HMRC receives the tax owed on your total taxable income for the year.
Understanding how the system works is the foundation for checking whether yours is calculated correctly.
What is the personal allowance for income tax?
The personal allowance is the amount of income you can earn each year before income tax becomes payable. It is the starting point for every income tax calculation in the UK.
Once your income exceeds the personal allowance, only the amount above it is taxable.
The allowance applies to most people regardless of whether they are employed, self employed, or receiving a pension.
The personal allowance is not fixed permanently. It is set by the government and can change from one tax year to the next, so it is worth checking each year.
The current personal allowance figure, along with the thresholds at which it tapers for higher earners, is set each tax year and listed in the rates and bands section below.
One important exception applies to higher earners.
Above a certain income threshold, the personal allowance reduces gradually — by £1 for every £2 earned over that point — until it reaches zero entirely.
This taper creates an effective higher marginal rate in that income range, which is worth being aware of when planning pension contributions or other reliefs.
Understanding your personal allowance is one of the most important parts of working out what you owe.
Getting it wrong — or having it applied incorrectly by an employer — is one of the most common reasons people overpay income tax.
What are the UK income tax rates and bands for 2026/27?
Income tax in the UK operates on a banded system.
Each band applies to a specific portion of your income above the personal allowance, with a different rate charged on each portion.
A higher band does not mean all your income is taxed at that rate — only the portion that falls within each band is charged at that band’s rate.
Scotland operates a separate system with different bands and rates released by the Scottish government..
The figures below apply in England, Wales, and Northern Ireland.
2026/27 income tax bands:
- Personal allowance up to £12,570 at 0%.
- Basic rate £12,571 to £50,270 at 20%.
- Higher rate £50,271 to £125,140 at 40%.
- Additional rate over £125,140 at 45%.
The personal allowance taper begins at £100,000 and reaches zero at £125,140.
These thresholds are currently frozen until at least April 2031, meaning that rising wages can move people into higher bands over time even when rates stay the same.
Savings and dividend income carry their own allowances and rates within this framework.
2026/27 savings and dividend figures:
- Personal savings allowance or PSA for short, £1,000 (basic rate) and £500 (higher rate), nil for additional rate taxpayers.
- Dividend allowance £500, with dividend income above that taxed at 10.75% (basic), 35.75% (higher), and 39.35% (additional rate).
You can use the income tax calculator on this site to work out your own position based on your earnings and tax year.
What income is tax free in the UK?
Not every pound you receive is subject to income tax.
Understanding which income types are taxable and which are not is a practical part of managing your tax position.
The following types of income are not subject to income tax:
- Interest earned within a cash ISA or stocks and shares ISA.
- Most state benefits, including housing benefit and child benefit.
- Winnings from Premium Bonds or the National Lottery.
- Student loans and grants.
- Maintenance payments received from a former spouse or partner.
- Income within your personal allowance.
The following types of income are taxable:
- Wages, salaries, and most employment bonuses.
- Self employed trading profits.
- Pension income, whether from a private, workplace, or state pension.
- Rental income above the relevant allowance thresholds.
- Interest on savings above your personal savings allowance.
- Dividend income above the dividend allowance.
Several smaller allowances also reduce the amount of income on which you pay tax.
The trading allowance, the property income allowance, and the rent a room scheme each allow you to receive a set amount of income from specific sources without paying tax on it.
The thresholds for these tax allowances are reviewed and reset annually from the beginning of the tax year.
For a full breakdown of available allowances, refer to the income tax rates and allowances guidance on GOV.UK.
How the self employed pay income tax in the UK
Income tax for self employed people operates differently to PAYE. There is no employer to deduct tax on your behalf, so the responsibility for calculating and paying what you owe falls to you.
You do this through a Self Assessment tax return — an annual declaration to HMRC of everything you earned, what you spent running your business, and what tax you owe on the difference.
The process follows four steps:
- Record all income received during the tax year, which runs from 6 April to 5 April.
- Deduct your allowable business expenses — costs incurred solely to run your business, such as equipment, professional subscriptions, and business travel.
- The remainder is your taxable profit. Income tax is charged on that figure above your personal allowance, at the standard rates and bands.
- Submit the return to HMRC by the deadline and pay any tax owed.
Making Tax Digital for ITSA is being introduced in phases, requiring more frequent digital reporting for those above certain thresholds — check GOV.UK for current requirements.
Under Making Tax Digital for Income Tax, the annual Self Assessment tax return is replaced by a final declaration — a year-end summary submitted to HMRC by 31 January following the end of the tax year.
Claiming every allowable expense reduces your taxable profit directly, so thorough record-keeping throughout the year is one of the most effective ways to keep your bill down.
HMRC can request evidence for any figure on a return, and errors or omissions can result in penalties.
Pension contributions reduce your taxable income in the same way as for employed people, making them one of the most tax-efficient options available to the self employed.
Ways to reduce your income tax in the UK
There are legitimate ways to reduce how much income tax you pay, and they are available to both employed and self employed people.
The key is knowing what you are entitled to claim and acting within the relevant timescales. The most commonly used routes are:
- Employment expenses: if you use your own money to pay for costs required to do your job — such as uniforms, tools, professional fees, or business mileage — you may be entitled to claim tax relief. HMRC allows claims going back four tax years, so previous years are worth checking too.
- Self employed expenses: every allowable business cost you claim reduces your taxable profit, which directly reduces your income tax liability. Thorough record-keeping throughout the year is the most effective way to make sure nothing is missed.
- Pension contributions: paying into a registered pension scheme reduces your adjusted net income, which can keep you within a lower tax band or restore a personal allowance that would otherwise be tapered. This applies to both employed and self employed people.
- Marriage allowance: if your spouse or civil partner earns below the personal allowance, a portion of their unused allowance can be transferred to you, reducing your tax bill. The transferable amount is set each tax year.
Many people assume they are already paying the right amount of tax and miss out as a result. You can find out whether you are owed a refund based on your circumstances.
How to check your income tax is correct in the UK
Paying the wrong amount of income tax is more common than most people realise.
Overpayments can happen for many reasons: a wrong tax code, a job change, working only part of a tax year, or not claiming expenses you are entitled to.
Your tax code is the most important number to check. It tells your employer how much of your income to treat as tax free before applying PAYE.
If the code is wrong, you could be overpaying every month without knowing it. You can check it through your payslip, a P60, or your personal tax account / HMRC App on GOV.UK.
If you think your code is incorrect, contact HMRC. Overpayments found during the tax year are typically corrected through your remaining monthly pay, and those identified after the year ends are usually refunded directly.
Your P60 is also worth checking at the end of each tax year end. It shows your total income and total tax deducted — comparing the two against what you expected to pay is a straightforward way to spot errors.
Income tax affects almost every working adult in the UK, yet many people pay more than they owe simply because they do not know what to check.
Understanding what is income tax UK law requires you to pay — and knowing how the personal allowance, tax codes, and available reliefs interact — puts you in a much stronger position than most.
Whether you are employed under PAYE or managing your own Self Assessment return, the same principle applies: understand how income tax is calculated and you are far better placed to make sure yours is right.
For a full breakdown of current rates, thresholds, and what they mean for your take-home pay, the guide to income tax rates and bands covers the detail.
Key Takeaways
Key points from this UK income tax guide:
- Income tax is charged on earnings above your personal allowance — the portion of your income you can earn each year without paying any income tax.
- The UK uses a banded system, meaning only the portion of your income in each band is taxed at that band’s rate — moving into a higher band does not mean all your income is taxed at the higher rate.
- PAYE employees have income tax deducted automatically by their employer each month; self employed people calculate and pay their own tax through a Self Assessment return.
- Not all income is taxable — ISA interest, most state benefits, and income within your personal allowance are among the types that attract no income tax.
- Employment expenses, pension contributions, and available allowances can all reduce your taxable income — and claims for overpaid tax can be made up to four years back.
- Checking your tax code regularly is one of the simplest ways to confirm you are not overpaying income tax through PAYE.
These are the core principles that underpin every income tax calculation in the UK.
Income Tax UK FAQs
How does income tax work in the UK?
Income tax in the UK is charged on earnings above your personal allowance. Different portions of your income are taxed at different rates depending on which band they fall into. Employed people pay through PAYE, where the employer deducts tax automatically each month. Self employed people report their income and pay through Self Assessment or making tax digital submissions directly to HMRC.
What is the personal allowance for income tax in the UK?
The personal allowance is the amount you can earn before paying income tax. For tax year 2026/27 it is £12,570. Only income above this threshold is subject to income tax. If your income exceeds £100,000, your personal allowance reduces gradually until it reaches zero at £125,140.
Do I pay income tax on all my income?
No. Some income is tax free, including ISA interest, most state benefits, Premium Bond winnings, and income within your personal allowance. Taxable income includes wages, self employed profits, pension income, and rental income above relevant thresholds. The type of income determines whether it is subject to income tax.
How is income tax calculated for the self employed?
Self employed people calculate their income tax through Self Assessment. You report your total income, deduct allowable business expenses, and pay tax on the resulting taxable profit above your personal allowance. The standard income tax rates and bands apply in the same way as for employed people. Accurate record-keeping throughout the year is essential to avoid errors or penalties.
How can I pay less income tax in the UK?
There are several legitimate ways to reduce your income tax bill. Employed people can claim tax relief on work-related expenses including uniforms, tools, and business mileage. Pension contributions reduce your adjusted net income, potentially keeping you in a lower tax band. HMRC allows claims going back four tax years, so it is worth checking whether you have missed any relief in previous years.
