You do if, for example, you were self-employed with more than £1,000 of income, or made more than £2,500 of rental profit, and for 2025/26 the online return and any tax are due by 31 January 2027.
An employee on a £30,000 salary who rented out a flat with no mortgage in 2025/26
| Salary, taxed through PAYE | £30,000.00 |
| Rent received in 2025/26 | £9,000.00 |
| Less allowable expenses (agent, repairs, insurance) | −£5,800.00 |
| Rental profit | £3,200.00 |
| Rental profit above which a return is needed | £2,500.00 |
| Income tax: £3,200 at 20% | £640.00 |
| Tax due by 31 January 2027 | £640.00 |
The bill is under £1,000, so there are no payments on account for 2026/27.
England. The salary is taxed through PAYE and uses the whole personal allowance. All assumptions and rates
Assumptions and rates
- England. The salary is taxed through PAYE and uses the whole personal allowance.
- The flat is owned outright by one person, so there are no finance costs.
- No other income.
- Rental profit over £2,500 after expenses, or rent over £10,000 before them, means a return
- Income tax 20%, because the profit stays inside the basic rate band
Who has to file?
You need to send a return for the last tax year if any of these applied: you were self-employed as a sole trader and earned more than £1,000 before expenses; you were a partner in a business partnership; you had capital gains tax to pay; or you had to pay the High Income Child Benefit Charge and are not paying it through PAYE.
Untaxed income can also bring you in, such as rent, tips, or income from abroad.
What are the thresholds for rent?
The first £1,000 of rental income is covered by the property allowance. Between £1,000 and £2,500, you contact HMRC. Above £2,500 after allowable expenses, or £10,000 before them, you file a return.
Does Child Benefit mean I need to file?
It can. If your income is over £60,000 and you or your partner get Child Benefit, the charge claws back 1% of it for every £200 above £60,000, and all of it at £80,000. Employees can now pay the charge through PAYE instead of filing, unless they need a return for another reason.
What are the dates?
For the 2025/26 tax year: register by 5 October 2026 if you are new to Self Assessment or did not file last year, send a paper return by 31 October 2026, and file online and pay by 31 January 2027.
For 2026/27, each date moves on a year: 5 October 2027, 31 October 2027 and 31 January 2028.
What if I miss the deadline?
A late return brings an initial £100 penalty, with daily penalties after three months and more after six and twelve months. Interest runs on tax paid late, and late payment brings penalties of its own.
Will Making Tax Digital replace the return?
For sole traders and landlords over the income thresholds, quarterly updates are added and the return becomes a final declaration. When does Making Tax Digital start for me? explains who is affected and when.
What this doesn’t cover
- Partnership returns, trust returns and company tax returns.
- People who are not UK resident.
- Scottish income tax rates.
- Rent from a room in your own home under the Rent a Room scheme.
Common questions
Usually not, because PAYE collects the tax. You may need to if something from the list above applies, such as the High Income Child Benefit Charge and you are not paying it through PAYE.
No. It is the date to register for Self Assessment. The return itself is due by 31 October on paper or 31 January online.
A short email before each deadline that costs money to miss, and when a new guide goes up.