There is an online tool, developed by HMRC, that allows taxpayers to check if they need to notify HMRC about additional income. The online tool can be found at www.gov.uk/check-additional-income-tax.
You are required to submit a self-assessment return if any of the following apply:
- you were self-employed as a ‘sole trader’ and earned more than £1,000 (before taking off anything you can claim tax relief on);
- you were a partner in a business partnership;
- you had a total taxable income of more than £150,000 in 2023-24 (£100,000 in 2022-23);
- you had to pay Capital Gains Tax when you sold or ‘disposed of’ something that increased in value; or
- you had to pay the High Income Child Benefit Charge.
You may also need to send a tax return if you have any untaxed income, such as:
- money from renting out a property;
- tips and commission;
- income from savings, investments and dividends; or
- foreign income.
There could be other reasons why you may be required to register for self-assessment and therefore using HMRC’s online tool can help you check if you are required to submit a return.
If you’re unsure whether additional income means you need to register for Self‑Assessment or submit a tax return, getting professional advice early can help you stay compliant and avoid penalties. At CIGMA Accounting, we regularly support contractors, online businesses, landlords, and limited companies, helping individuals understand when untaxed income must be declared and how to meet HMRC Self‑Assessment obligations correctly.
Our experienced accountants support clients through our London offices in Farringdon and Hammersmith, as well as surrounding areas including Moorgate, Liverpool Street, Brook Green, and Ravenscourt Park, providing clear guidance on additional income reporting, Self‑Assessment registration, and ongoing compliance.
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