The common reasons you need to file
For the 2025/26 tax year (6 April 2025 to 5 April 2026), you'll usually need a Self Assessment tax return if any of these apply:
- You were self-employed and earned more than £1,000 before expenses (the trading allowance).
- You were a partner in a business partnership.
- You had untaxed income over £2,500, for example tips, commission or side income not taxed through PAYE.
- You had more than £10,000 of savings interest or dividends.
- You made capital gains above the £3,000 annual exempt amount, or need to report a gain.
- You or your partner got Child Benefit and your income was over £60,000 (the High Income Child Benefit Charge), unless you pay it through PAYE.
Situations that often mean a return
- Rental income over £1,000 a year.
- Foreign income, such as overseas rent or investments.
- Company directors with income not taxed through PAYE, such as dividends.
These depend on the amounts and how the tax is collected, which is why the checker marks them as “worth checking”.
What changed recently
From 2023/24, earning over £150,000 through PAYE no longer means you must file on its own. From 2024/25, the Child Benefit charge threshold rose to £60,000, with the full benefit repaid at £80,000.
If you need to file
- Register for Self Assessment by 5 October 2026 if it's your first time. HMRC posts your UTR number.
- Gather your documents: P60, payslips, bank interest, rental statements, invoices and receipts.
- File online and pay by 31 January 2027.
TaxGo reads your documents, asks only what's missing and prepares the return for you to check and approve, for £79. The checker above is a guide only. HMRC's official tool has the final say.