Do employees need to do Self Assessment?

Most employees do not need to file a Self Assessment tax return. PAYE takes Income Tax from your wages, and HMRC adjusts your tax code for small amounts of other income. You do need a return if you have income PAYE cannot handle, such as self-employed work, rental income or large savings and dividend income, or if you or your partner has to pay the High Income Child Benefit Charge. Gov.uk has an online checker that tells you in a few minutes whether you need to file.

Situations that usually mean a return

You are likely to need Self Assessment if, during the tax year (6 April to 5 April), any of these applied:

• you were self-employed alongside your job, for example private tutoring, private clinical work, photography or selling goods regularly
• you received rent from a property, including letting a room above the level of the rent-a-room scheme
• you had to pay the High Income Child Benefit Charge, because your adjusted net income was over £60,000 and you or your partner got Child Benefit
• you had dividend income above the £500 dividend allowance that could not be collected through your tax code
• you had large amounts of savings interest above your Personal Savings Allowance
• you made a capital gain that is taxable, such as selling shares or a second property
• you received income from abroad
• you were a company director, with some exceptions
• HMRC sent you a notice to file a return

Some of these, especially small amounts of untaxed savings interest or dividends, can sometimes be collected through your tax code without a return. HMRC decides which route applies.

Common public sector triggers

Within the public sector the cases that come up most are:

• doctors with private practice, locum work through a limited company, medico-legal reports or fees for teaching and examining
• teachers who tutor privately, mark exam papers paid without tax, or write educational resources
• nurses and allied health professionals doing private aesthetics or physiotherapy alongside NHS work
• senior staff above £60,000 with Child Benefit, through the High Income Child Benefit Charge
• higher rate taxpayers in a relief at source pension who want to claim the extra tax relief

Bank, agency and supply work does not normally count, because it is paid through PAYE.

Savings and dividends

The tax-free amounts for savings interest are £1,000 for basic rate taxpayers and £500 for higher rate taxpayers, with nothing for additional rate taxpayers. There is also a 0 per cent starting rate on up to £5,000 of savings interest, available in full only if your other taxable income is under £17,570. Dividends get a £500 allowance, and above that are taxed at 10.75 per cent at the basic rate, 35.75 per cent at the higher rate and 39.35 per cent at the additional rate in 2026/27.

Interest in an ISA does not count. Our guides to tax on savings interest and dividend tax for employees with shares go into the detail.

Deadlines and registration

If you need to file for the first time, register with HMRC by 5 October after the end of the tax year. For the 2026/27 tax year, which ends on 5 April 2027, that means by 5 October 2027. The online return and any tax due must then be in by 31 January after the end of the tax year, so 31 January 2028 for 2026/27.

Paper returns have an earlier deadline. Penalties apply for late registration, late filing and late payment, and they add up quickly. Gov.uk lists them.

Once registered, you get a Unique Taxpayer Reference (UTR) and file through your HMRC online account. The personal tax account guide explains how to set up access.

How a return fits with PAYE

Your return includes your PAYE pay and the tax already taken, from your P60. HMRC then works out the total tax due and takes off what PAYE has already paid. If you owe less than a set amount and file online on time, you can usually ask for the balance to be collected through your tax code the following year.

If your other income is regular, HMRC may ask for payments on account, which are advance payments towards the next year’s bill. That can make the first January payment larger than expected.

Making Tax Digital

HMRC is moving some self-employed people and landlords onto Making Tax Digital for Income Tax, which means keeping digital records and sending quarterly updates. Whether it applies depends on your income from self-employment and property, and the thresholds are being phased in. Gov.uk has a checker. Employees with only PAYE income are not affected.

If you are unsure whether something you earn counts as trading, HMRC’s helpline can advise, and the tax charities TaxAid and Tax Help for Older People help people on low incomes for free. For more complex affairs, an accountant or chartered tax adviser can file for you.