Most people who only have a salary taxed through PAYE don't need to file a Self Assessment tax return. But if any of the following applies, take a closer look.
You must file if
you're self-employed and earned more than £1,000, before taking off expenses
you're a partner in a business partnership
you have Capital Gains Tax to pay
you have to pay the High Income Child Benefit Charge and don't pay it through PAYE
You may need to file: income that hasn't been taxed
Rental income: you need to file if it's £2,500 or more after expenses, or £10,000 or more before expenses. See the rental income guide.
Tips and commission
Savings interest: you must file if it's over £10,000. See the savings interest guide.
Dividends and investment income
Foreign income: see the foreign income guide.
Side work, selling online and working through platforms
The £1,000 trading allowance: if your side income for the year is £1,000 or less before expenses, you don't need to tell HMRC. If it's more, register for Self Assessment and file a return. You can then deduct either the £1,000 allowance or your actual expenses, not both.
What counts: buying things to resell, making things to sell, or providing services through a platform, such as delivery work, holiday lets, babysitting or gardening. Selling your own used belongings usually doesn't count.
Platforms tell HMRC: since 2024, platforms such as eBay, Vinted and Airbnb have to report sellers who make at least 30 sales or about £1,700 in a year. It isn't a new tax and doesn't automatically mean you need to file, but HMRC will have the information.
Readers ask: if my second, part-time job pays over £1,000, do I need to file?
It depends on the type of income. If your second job pays you a wage taxed through PAYE (usually on a BR tax code), the £1,000 threshold doesn't apply, and that job alone usually doesn't mean you need to file. The £1,000 threshold is for self-employment and side income.
Still not sure?
Answer a few questions in GOV.UK's "Check if you need to send a Self Assessment tax return" tool. It doesn't send your details to HMRC.
If HMRC has written asking you to file, you must file by the deadline in the letter. If you think you don't need to, contact HMRC.
Key dates (2025 to 2026 tax year)
Date
What
5 October 2026
Register if you're filing for the first time
31 October 2026
Paper return deadline
31 January 2027
Online return and payment deadline
Sources checked: 1 October 2026 · Tax year: 2025 to 2026 · Sources are official GOV.UK pages.
This is general information, not tax advice for your situation. How it applies depends on your full circumstances.