Tax can feel like one of those topics you are supposed to already understand but never had the chance to learn properly. The good news is that the rules are simpler than they look once you know the basics. At Fast Loan UK, we are an FCA authorised short term lender with over a decade of experience helping people in the UK manage their money sensibly, and we have written this guide to demystify the UK tax system in plain English. Whether you are starting a new job, picking up a side hustle, or simply trying to budget better, understanding how the tax year works will help you keep more of your money and avoid nasty surprises from HMRC.
The UK tax year starts on 6 April and ends on 5 April the following year. The current tax year is 2026/27, which runs from 6 April 2026 to 5 April 2027. These dates apply to personal income tax, the Personal Allowance, ISA allowances and Self Assessment, and they are the same for every individual taxpayer across England, Wales, Northern Ireland and Scotland.
The 6 April start date is a leftover from the move from the Julian to the Gregorian calendar in 1752. Before the switch, the financial year began on 25 March, known as Lady Day. To avoid losing 11 days of tax revenue when the calendar shifted, the Treasury moved the start of the tax year forward to 5 April, and then to 6 April in 1800. The dates have stayed there ever since. It is an odd quirk, but it is the reason your Personal Allowance resets on 6 April rather than 1 January.
These three terms get confused often, but they mean different things in the UK:
If you are an employee, the only one you usually need to think about is the personal tax year.
Missing a tax deadline can mean automatic penalties from HMRC, so it is worth marking these dates in your calendar. For the 2026/27 tax year, the key dates are:
If you are employed under PAYE, your tax is taken automatically from your wages and you usually do not need to file a Self Assessment return. If you are self-employed, a landlord, a company director or earn over £150,000, you almost certainly do.
Income Tax is the tax you pay on most types of income, including wages from employment, profits from self-employment, pension income, rental income from property, and most state benefits. It is collected by HM Revenue and Customs (HMRC) and funds public services such as the NHS, schools, roads and welfare.
The amount you pay depends on how much you earn in a tax year and which tax band each slice of your income falls into. The UK uses what is called a marginal tax system, which means only the portion of your income that falls into a higher band is taxed at the higher rate. Crossing into the higher rate band does not mean all of your income is suddenly taxed at 40%, a misconception confirmed by the Low Incomes Tax Reform Group as one of the most common misunderstandings UK taxpayers have about how income tax works.
The Personal Allowance is the amount you can earn each tax year before you start paying any Income Tax. For 2026/27, the standard Personal Allowance is £12,570, and it has been frozen at this level since 2021/22. The 2025 Autumn Budget confirmed that this freeze will continue until April 2031.
If you earn more than £100,000, your Personal Allowance is reduced by £1 for every £2 you earn above that threshold. By the time your income reaches £125,140, your Personal Allowance is gone entirely. This creates an effective marginal rate of 60% on income between £100,000 and £125,140, often called the 60% trap.
| Band | Taxable income | Rate |
| Personal Allowance | Up to £12,570 | 0% |
| Basic rate | £12,571 to £50,270 | 20% |
| Higher rate | £50,271 to £125,140 | 40% |
| Additional rate | Over £125,140 | 45% |
Scotland sets its own Income Tax bands for non-savings, non-dividend income. Scottish taxpayers in 2026/27 pay a starter rate of 19%, a basic rate of 20%, an intermediate rate of 21%, a higher rate of 42%, an advanced rate of 45% and a top rate of 48%, with thresholds different from those in the rest of the UK.
If you live in England and earn £40,000 in 2026/27, the maths is simple:
You will also pay Class 1 National Insurance at 8% on earnings above £12,570, which adds £2,194.40, leaving you with take-home pay of around £32,319 before any pension or student loan deductions.
There are two main ways tax is collected in the UK.
Pay As You Earn (PAYE) is used by most employees. Your employer takes Income Tax and National Insurance from your wages before they pay you, using a tax code issued by HMRC. The tax code tells your employer how much tax-free income you are entitled to. A standard tax code for 2026/27 is 1257L, which reflects the £12,570 Personal Allowance.
Self Assessment is the system used by people whose tax is not fully collected through PAYE. This includes the self-employed, landlords, company directors, those with large investment income, and anyone earning over £150,000. If you fall into one of these groups, you need to register with HMRC and submit a Self Assessment tax return each year.
It is worth checking your tax code at the start of every tax year. The wrong code can mean you pay too much or too little tax, and HMRC does not always spot it automatically. You can review your tax code through your Personal Tax Account on the GOV.UK website.
National Insurance (NI) is a separate tax on earnings that builds your entitlement to the State Pension and certain benefits. For 2026/27, employees pay 8% NI on earnings between £12,570 and £50,270, and 2% on earnings above that. Self-employed people pay Class 4 NI on their profits at similar rates.
An Individual Savings Account (ISA) lets you save or invest up to £20,000 each tax year without paying tax on the interest, dividends or capital gains. The £20,000 ISA allowance resets on 6 April each year and cannot be carried into the next tax year, so if you do not use it, you lose it. From the 2026/27 tax year, you can spread your allowance across multiple ISAs of the same type, so you could pay into more than one Cash ISA or more than one Stocks and Shares ISA in the same year.
If you own shares or hold money in savings accounts outside an ISA, the income you receive is taxed separately. For 2026/27, the Dividend Allowance is £500, and dividend tax rates rose to 10.75% for basic rate taxpayers, 35.75% for higher rate taxpayers and 39.35% for additional rate taxpayers. The Personal Savings Allowance lets basic rate taxpayers earn up to £1,000 of interest tax-free and higher rate taxpayers up to £500.
If you sell an asset such as a second property, shares outside an ISA, or valuable possessions, you may need to pay Capital Gains Tax on the profit. The annual exempt amount for 2026/27 is £3,000, so gains below this are tax-free. Anything above is taxed at rates that depend on your Income Tax band and the type of asset.
Understanding the tax year is not just an admin task. It directly affects how much you take home each month and how far that money goes. Here are the practical implications worth thinking about.
Because the Personal Allowance and the higher rate threshold are frozen until April 2031, every pay rise you receive between now and then is taxed in full, with no compensating increase in your tax-free amount. This is known as fiscal drag, and it pulls more workers into higher tax bands each year as wages rise. Building this into your budget helps you avoid the surprise of a smaller-than-expected take-home increase after a pay rise.
Most tax allowances reset on 6 April and cannot be rolled into the next year. That includes your ISA allowance, your Capital Gains Tax allowance and the pension annual allowance. If you have spare cash and a goal in mind, using these allowances before the tax year ends is one of the simplest ways to keep more of your money. If you are not sure where to start, our guide on how to budget money effectively walks through a simple framework for working out what you can afford to set aside.
When you start a new tax year, HMRC may issue you a new tax code based on the information they hold. A wrong code is one of the most common reasons people overpay or underpay tax. If you have had a pay rise, started a new job, changed pension contributions, or began receiving benefits in kind, your code may need updating. You can do this through your Personal Tax Account at GOV.UK.
If you are self-employed or have multiple income streams, your tax bill may not be predictable. The general rule of thumb is to set aside 20% to 30% of your self-employed income for tax and National Insurance. Holding it in a separate savings account stops you spending it by accident. Our guide on how to automate your savings explains how to set this up so the money moves before you see it.
If you submit a Self Assessment return, you also pay your tax bill on 31 January. That falls just after Christmas, which is a high-pressure month for most household budgets. Setting aside a little each month from October onwards can spread the load. Our guide on managing your money during the festive period covers practical ways to keep Christmas costs from disrupting your January tax payment.
Tax rules change every year, and the safest source is always HMRC and the UK government itself. For day-to-day questions and your personal tax records, GOV.UK’s Income Tax pages cover the basics, and your Personal Tax Account shows your live tax position. For free, independent help if you are on a low income or struggling, the Low Incomes Tax Reform Group and the charity TaxAid both publish trustworthy guides written by qualified tax advisers. For wider money worries, MoneyHelper, set up by the UK government, offers free and impartial guidance.
The UK tax year starts on 6 April and ends on 5 April the following year. The 2026/27 tax year runs from 6 April 2026 to 5 April 2027.
The 6 April start date dates back to the calendar reform of 1752, when the UK switched from the Julian to the Gregorian calendar. To avoid losing tax revenue from the missing days, the start of the tax year was shifted, and it has stayed on 6 April since 1800.
For the 2026/27 tax year, you can earn up to £12,570 before paying any Income Tax. This is the standard Personal Allowance and is frozen at this level until April 2031.
Most employees do not, because their tax is collected automatically through PAYE. You usually need to file a Self Assessment tax return if you are self-employed, a landlord, a company director, earn over £150,000, or have untaxed income such as significant savings interest or dividends.
HMRC issues an automatic £100 penalty if you miss the 31 January online filing deadline, even if you have no tax to pay. Further penalties and daily interest apply if you delay paying or filing for several months.
You can check your tax code through your Personal Tax Account on GOV.UK, on your most recent payslip, or on your annual P60. If you think it is wrong, contact HMRC directly. A standard tax code for the 2026/27 tax year is 1257L.
Tax is rarely anyone’s favourite subject, but understanding the basics gives you real control over your money. Knowing the tax year dates, your Personal Allowance and how the bands work means you can plan ahead, use your allowances, check your tax code and avoid the kind of surprises that throw a budget off course. We are not tax advisers, and if your situation is complex you should always speak to a qualified accountant or contact HMRC directly. But for the everyday questions most people have about how tax works in the UK, we hope this guide makes the rules feel less daunting and a little more useful.
If your finances ever come under unexpected pressure, our responsible lending team is here to help with short term borrowing that fits your circumstances. We are authorised and regulated by the Financial Conduct Authority (firm reference number 673907), and we believe transparency, fairness and treating customers right should sit at the heart of every financial decision, including the ones you make about tax.
Warning: Late repayment can cause you serious money problems. For help, go to moneyhelper.org.uk.
