Who Must Submit a Self Assessment Tax Return in the UK?

You must submit a Self Assessment tax return if, during the tax year (6th April to 5th April), any of the following apply:

• You were self-employed as a sole trader and earned more than £1,000 before expenses.
• You were a partner in a business partnership.
• Your total taxable income exceeded £150,000.
• You had Capital Gains Tax to pay after selling assets.
• You were liable for the High Income Child Benefit Charge.
• You received untaxed income, such as rental income, dividends, foreign income, savings interest, tips or commission.

If you have not previously filed, you must register for Self Assessment by 5th October following the end of the tax year.

You may also file voluntarily to claim tax reliefs, pay voluntary National Insurance, or prove self-employed status for benefit purposes.

If your self-employed or property income exceeds the threshold, you are now required to follow Making Tax Digital (MTD) rules for digital record-keeping and quarterly updates.