You must send a self assessment tax return if HMRC asks you for one, or if in the tax year you earned more than £1,000 from self-employment before expenses, were a partner in a business, had capital gains tax to pay, or had income that reached you untaxed, such as rent above the reporting lines or more than £10,000 of savings interest or dividends. If it is your first return for the year that ended on 5 April 2026, you have to tell HMRC by 5 October 2026.
- £1,000of self-employed income, before expenses, and a return is due
- £2,500of rental profit, or £10,000 of rent before expenses
- £10,000of savings interest, or of dividends
- 5 Octoberto tell HMRC, if this is your first return
Who must file a tax return.
Self assessment is how HMRC collects income tax that was not taken at source. Wages and pensions are taxed before they are paid, through PAYE. Other income is not, and the return is where it is reported. The tax year runs from 6 April to 5 April, and the return is filled in after it ends.
You must send a return if any of these applied to you in the tax year:
- you were self-employed as a sole trader and earned more than £1,000, counted before any expenses are taken off
- you were a partner in a business partnership
- you had capital gains tax to pay, because you sold or gave away something that had gone up in value
- you had to pay the High Income Child Benefit Charge and are not paying it through PAYE
- you are an off-payroll worker repaying a student or postgraduate loan
A return HMRC has asked for is always due. If HMRC has written to you asking for a return, you have to send it by the date on the letter, even if you think there is nothing to pay. If you believe you should not have been asked, tell HMRC rather than leaving the letter unanswered.
The £1,000 line for the self-employed is measured on what you were paid, not on what was left. Sales of £1,400 with costs of £900 are over the line, although the profit is £500.
Untaxed income: where the lines are.
You may also need a return if you had income that reached you without tax being taken off: rent, tips and commission, savings interest, dividends or income from abroad. For the three most common, GOV.UK gives the figures.
| Income | Nothing to report | Tell HMRC | Return needed |
|---|---|---|---|
| Rent | £1,000 or less | Over £1,000, up to £2,500 | Over £2,500 after expenses, or £10,000 before them |
| Savings interest | Within your allowances | Tax to pay, on £10,000 or less | Over £10,000 |
| Dividends | £500 or less | Tax to pay, on up to £10,000 | Over £10,000 |
Below the return line the tax is collected another way. Banks and building societies report interest to HMRC after 5 April, and HMRC sends a calculation to people who are employed or have a pension, usually collecting the tax through their tax code. For dividends, ask HMRC to change your tax code, or call its helpline, after the tax year ends and before 5 October.
The savings allowances
A basic rate taxpayer can receive £1,000 of interest free of tax, and a higher rate taxpayer £500. An additional rate taxpayer has no allowance. If your other income is below £17,570 you may also have some or all of the £5,000 starting rate for savings. Interest inside an ISA is not counted at all.
Child Benefit
If you or your partner receive Child Benefit and one of you has income over £60,000, the higher earner pays some of it back: 1% for every £200 over the line, and all of it at £80,000. The charge can be paid through your tax code. It has to go on a return if you need one for any other reason.
Tips, commission and income from abroad
GOV.UK gives no single figure for these. HMRC’s own checker on GOV.UK asks a few questions and tells you whether a return is needed. It does not send your answers to HMRC.
Who does not need to file.
If all of your income is wages or a pension taxed through PAYE, and nothing in the list above applies, you do not need a return. That is the position of most people in work.
Being a company director is not on HMRC’s list either. What decides it is the income you took: a director whose only income is a salary through PAYE and dividends inside the £500 allowance has nothing to report, while one who took £20,000 of dividends does.
Filing by choice
Some people send a return although they are not required to. GOV.UK names three reasons: to prove that you are self-employed, for example to claim Tax-Free Childcare or Maternity Allowance; to pay voluntary National Insurance contributions; and to claim income tax relief on maintenance payments.
If you no longer need to file
If you have stopped being self-employed, no longer let property or no longer pay the Child Benefit charge, tell HMRC as soon as you can. There is an online service for it. HMRC needs time to review the request before 31 January, and a return that is still on its records as due brings a penalty if it does not arrive.
Three people, worked through.
Worked examples, tax year 2025 to 2026
All three are employed and taxed through PAYE
None of them has ever sent a return. The question for each is whether the year that ended on 5 April 2026 is the first.
- Amira sells candles online
- Sales in the year, before any costs£1,650
- Wax, jars, postage and fees£700
- Sales are over £1,000, so a return is dueRegister by 5 October
- Tom lets a flat
- Rent received in the year£7,200
- Allowable expenses£5,200
- Profit£2,000
- Under both return lines, over £1,000 of rentContact HMRC
- Helen has savings and a few shares
- Salary£48,000
- Savings interest, against an allowance of £1,000£320
- Dividends, against an allowance of £500£400
- Everything is inside her allowancesNothing to do
Amira’s profit is only £950, and the tax on it at 20% is £190. The return is still due, because the test is on sales. Tom does not need a return for his rent, but he cannot stay silent: rent over £1,000 has to be told to HMRC. If his rent rose above £10,000, or his profit above £2,500, he would move into self assessment.
What to do next.
If you need a return for the 2025 to 2026 tax year and have not sent one before, you have to tell HMRC by 5 October 2026. The same date applies if you were registered in the past but did not need a return for 2024 to 2025. You tell HMRC by registering for self assessment, and you can be charged a penalty for doing it late.
- Check. Use the lines in this note, or HMRC’s checker if your case is not covered.
- Register, and wait for your Unique Taxpayer Reference. How to register and get a UTR has the steps.
- File online and pay by 31 January 2027. Deadlines and penalties has every date.
If 5 October has already passed, register anyway, today. HMRC will write with a date to file by, three months from its letter. The tax itself is still due by 31 January 2027, whatever date the letter gives.
The self assessment page sets out who we file for, and what each kind of return involves.
Questions, answered.
Not if your wages are your only income. PAYE has already collected the tax. You need one if, as well as the job, you earned more than £1,000 from self-employment before expenses, had rent above the reporting lines, had capital gains tax to pay, or received more than £10,000 in savings interest or in dividends. You also need one if HMRC has asked you for it.
Usually not. Income from self-employment or casual work of £1,000 or less in the tax year, before expenses, is covered by the trading allowance. Keep a record of it. You still have to register if you want to claim a loss, pay voluntary Class 2 National Insurance, or claim Tax-Free Childcare or Maternity Allowance on the strength of that work.
Being a director is not one of the reasons on HMRC’s list. A director needs a return if they have income that must be reported: dividends over £10,000, for example, or rent, or a capital gain. Dividends with tax to pay of up to £10,000 can be dealt with by asking HMRC to change your tax code instead.
Tell HMRC, and do it early. There is an online service for saying that you no longer need to send a return, or did not need one for an earlier year. Until HMRC agrees and withdraws the request, the return is still due and the penalties for lateness still apply.
Register now and bring the missing years up to date. A person who registers after 5 October and has not paid all of the tax by 31 January can be charged a failure to notify penalty, worked out on the tax that is still unpaid, so paying in full by that date matters more than anything else. We prepare a missing year for a fixed £150.
Keep reading.
Every figure in this note was checked against GOV.UK on 30 September 2026 and is for the 2026 to 2027 tax year unless it says otherwise. Desk Notes are general guidance for the UK, not advice on your own situation.
The number behind this noteIf you do need a return, see roughly what the bill will be with the sole trader tax estimate.
Open the tax estimateMore Desk Notes
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