Whether you are required to register for Self Assessment depends on your income sources and personal circumstances. This may apply even where most or all of your income has already been taxed through PAYE.
You will generally need to submit a Self Assessment tax return if you are self- employed as a sole trader and your gross trading income exceeds £1,000 before expenses. Individuals who are members of a business partnership are also normally required to file a tax return.
A Self Assessment return may also be required where total taxable income exceeds £150,000 for the 2026/27 tax year. However, individuals with lower levels of income may still fall within Self Assessment depending on their circumstances. This commonly applies where there are additional untaxed income sources, such as:
- Rental Income;
- Foreign Income;
- Savings or Investment Income; or
- Dividend Income.
Other common reasons for filing a tax return include: