Do I Need to File a Tax Return? The Self Assessment Rules for 2026

You need to file a Self Assessment tax return for 2026/27 if you were self-employed with gross income over £1,000, had untaxed income that HMRC cannot collect through your tax code, owe the High Income Child Benefit Charge, or HMRC has sent you a notice to file. A high salary on its own is no longer a reason: the old £100,000 and £150,000 income triggers have been removed for people taxed only through PAYE.

Most people never file. If all your income is a salary or a pension with tax deducted at source, and your savings interest and dividends are inside the allowances, there is normally nothing to send HMRC. The rest of this guide walks through each trigger so you can rule yourself in or out.

• Gross side income over £1,000 (before expenses) brings you into Self Assessment, even if you make a loss.
• The High Income Child Benefit Charge bites between £60,000 and £80,000 of adjusted net income.
• Total income over £150,000 is no longer a filing trigger by itself for PAYE-only taxpayers.
• If HMRC has issued a notice to file, you must file — or get the notice formally withdrawn. Ignoring it costs £100 minimum.
• Register by 5 October 2027 for the 2026/27 tax year; file online by 31 January 2028.

Who must file a tax return for 2026/27

Self Assessment is a collection mechanism, not a tax in itself. HMRC uses it when it cannot get the right amount of tax through PAYE. That gives you a short list of situations where a return is required.

Some smaller categories also apply automatically: trustees, personal representatives dealing with an estate's income, Church of England ministers, Lloyd's underwriters, and people with a tax charge on pension savings above the £60,000 annual allowance. Our do I need to file a tax return checker runs through the same questions in order and gives you a yes or no in under a minute.

Filing voluntarily to claim money back

You can file even when you do not have to. A return is the usual route for claiming higher-rate pension relief, higher-rate Gift Aid relief, or a large set of employment expenses. Employees with smaller claims — flat-rate uniform expenses, working-from-home relief, mileage shortfalls — can normally use a Personal Tax Account instead and avoid the annual return altogether.

If HMRC has already put you in Self Assessment

This is where most penalties come from. Once HMRC issues a notice to file, the legal obligation exists regardless of whether you actually owe anything. A nil return still has to be submitted. If the notice was sent in error, you can ask HMRC to withdraw it — there is a time limit, so do it early rather than hoping the record corrects itself.

Side income over £1,000: the test everyone gets wrong

The trading allowance is £1,000 of gross self-employment income a year, tax-free and with no need to register. The property allowance is a separate £1,000 for rental income. Two points catch people out:

• The test is on gross income, not profit. Turnover of £3,000 with £2,500 of costs still breaches the £1,000 threshold.
• The allowances are per person per source type, not per business. Two side hustles share one £1,000 trading allowance.

This applies to online selling of goods you have made or bought to resell, delivery driving, tutoring, dog walking, content income, freelance invoices and consultancy. Selling your own second-hand possessions is not trading at all, so it does not count.

Worked example: tutoring alongside a job

Priya earns £35,000 as an employee in England and invoices £3,500 for weekend tutoring, with £600 of costs.

1. Gross tutoring income of £3,500 is over £1,000, so she must register for Self Assessment.
2. She can deduct actual expenses of £600, or claim the £1,000 trading allowance instead. The allowance is bigger, so taxable profit is £3,500 − £1,000 = £2,500.
3. Her personal allowance and the whole of the basic-rate band are already used by her salary, so the £2,500 is taxed at 20% = £500.
4. Class 4 National Insurance is 6% on profits between £12,570 and £50,270. Her profits are £2,500, so no Class 4 is due.
5. Profits are below the £7,105 small profits threshold, so Class 2 at £3.65 a week is voluntary — she can pay it to protect a qualifying year towards the State Pension.

Total extra tax: £500, payable by 31 January after the end of the tax year. A Scottish taxpayer on the same figures would pay at the Scottish rate applying to that slice of income instead of 20%.

One change to keep on the radar: the government has said it intends to raise the Self Assessment reporting threshold for trading income from £1,000 to £3,000 of gross income later in this Parliament.. Separately, Making Tax Digital for Income Tax began in April 2026 for anyone with gross self-employment or property income over £50,000, which means quarterly updates as well as the annual return.

The High Income Child Benefit Charge

If you or your partner receive Child Benefit and the higher earner has adjusted net income over £60,000, a charge claws some of it back. The charge rises steadily and wipes out the full amount at £80,000. Child Benefit is £27.05 a week for the eldest child and £17.90 for each additional child.

Worked example: two children, £70,000 income

1. Annual Child Benefit: (£27.05 + £17.90) × 52 = £44.95 × 52 = £2,337.40.
2. Income above the threshold: £70,000 − £60,000 = £10,000.
3. Charge percentage: £10,000 ÷ £20,000 = 50%.
4. Charge for the year: £2,337.40 × 50% = £1,168.70.

Adjusted net income is the number that matters, and it is not the same as gross salary. Personal pension contributions and Gift Aid donations reduce it. Someone on £66,000 who makes a £6,000 gross pension contribution has adjusted net income of £60,000 and no charge at all.

Historically the only way to pay the charge was through a tax return. A PAYE route now exists so employed parents can have the charge collected through their tax code without registering for Self Assessment.. If you use the PAYE route and have no other trigger, no return is needed. If you are already in Self Assessment for any other reason, the charge goes on the return.

Why £150,000 is no longer a trigger

For years, high earners taxed entirely through PAYE had to file simply because of the size of their income. The threshold was £100,000, then rose to £150,000 for 2023/24, and was then removed completely. From 2024/25 onwards there is no income-level trigger for Self Assessment.

So a PAYE-only employee earning £200,000 does not have to file a return purely because of the salary. In practice, though, very high earners usually still file, because something else on the list applies:

• The tapered personal allowance. The £12,570 allowance reduces by £1 for every £2 of adjusted net income over £100,000 and disappears at £125,140. PAYE usually handles this through the tax code, but it often ends up estimated and wrong.
• The tapered pension annual allowance. The £60,000 allowance tapers once adjusted income exceeds £260,000, down to a £10,000 minimum. Any annual allowance charge must be reported on a return.
• Investment income. The dividend allowance is £500 and the personal savings allowance is nil for additional-rate taxpayers, so portfolios of any size generate taxable income.
• Higher-rate relief claims. Personal pension contributions and Gift Aid donations only get 20% relief at source; the rest is claimed back.

If you were taken out of Self Assessment by the threshold change and your circumstances have since altered, the obligation to tell HMRC falls on you. You have until 5 October after the end of the tax year to register.

Savings, dividends and capital gains

These three catch out people who have never filed before. Savings interest is covered by a personal savings allowance of £1,000 for basic-rate taxpayers, £500 for higher-rate and nil for additional-rate taxpayers, on top of the starting rate band of up to £5,000 for people with low earned income. Tax on modest amounts above the allowance is usually collected through your tax code rather than a return.

Dividends have a £500 allowance, then 10.75%, 35.75% and 39.35% equivalents by band. Larger dividend income normally needs a return.

Capital gains are reportable once total gains exceed the £3,000 annual exempt amount, with rates of 18% for gains in the basic-rate band and 24% above it. You also need to report if you want to register a loss for future use. Gains on UK residential property have their own 60-day reporting and payment deadline, separate from the annual return. There is also a proceeds-based reporting test for disposals even where no tax is due..

Deadlines and penalties

Miss the filing deadline and there is an automatic £100 penalty even if you owe no tax, with daily penalties building up after three months. Late payment carries separate interest and penalties..

Deregistering when you no longer need to file

Being in Self Assessment is not permanent, but you have to tell HMRC to leave. If you stop trading, sell the rental property, or your circumstances no longer match any trigger, use HMRC's online service to stop being self-employed or to tell HMRC you no longer need to send a return.

Three things to get right:

• File for the final year. If you traded for even part of 2026/27, that year's return is still due by 31 January 2028.
• Do not simply stop filing. Until HMRC confirms the record is closed, notices to file keep being issued and penalties keep accruing.
• Check your National Insurance. Ending self-employment ends Class 2 contributions. If you are short of qualifying years towards the State Pension, voluntary Class 3 at £18.40 a week is the alternative.

Deregistration does not erase earlier obligations. If a return from a previous year is still outstanding, closing the record for the future does not cancel it.

What to do next

Work through the triggers in order rather than guessing from your income level. The quickest way is the tax return checker, which asks about employment, side income, property, Child Benefit and gains and tells you whether a return is required for 2026/27. For a second opinion on an existing Self Assessment record — including whether you can come out of it — run the Self Assessment check. If the answer is yes, register with HMRC well before 5 October so your Unique Taxpayer Reference arrives in time.