How to Correct Mistakes on Your Sole Trader Self Assessment Tax Return in the UK
If you realise you’ve made an error on your Self Assessment tax return as a sole trader, it’s important to correct it promptly to avoid penalties or incorrect tax calculations. The process depends on how recently you submitted the return and the nature of the mistake.
Amending Your Tax Return Online
If you filed your return online through the HMRC Self Assessment service, you can usually make changes yourself by logging back into your account. Here’s what to consider:
- Time limit: You can amend your tax return within 12 months of the original filing deadline for that tax year. For example, if the deadline was 31 January 2024 for the 2022–23 tax year, you have until 31 January 2025 to make amendments.
- Scope of amendments: You can correct most details such as income figures, expenses, or allowances. However, if the amendment is complex or involves significant changes, it might be better to contact HMRC directly.
- How to amend: After signing in, select the relevant tax year, then choose “Amend Return.” Update the sections where you made errors and submit the corrected return.
If You Filed a Paper Return or Missed the Online Amendment Window
If you sent a paper tax return or the 12-month amendment window has passed, you cannot amend the return online. Instead:
- Contact HMRC: You should write to HMRC explaining the mistake and providing the correct information. Include your Unique Taxpayer Reference (UTR) and details of the tax year.
- Additional tax due: If correcting the mistake means you owe more tax, you should pay it as soon as possible to reduce any interest or penalties.
Examples of Common Mistakes and Corrections
- Underreported income: If you forgot to include some trading income, amend your return to add the missing amount. Keep records such as invoices or bank statements to support the correction.
- Overclaimed expenses: If you claimed more expenses than you actually incurred, correct the figures to avoid paying too little tax.
- Incorrect personal details: If you entered the wrong address or National Insurance number, update these details when amending your return or inform HMRC separately.
What Happens After You Amend Your Return?
HMRC will recalculate your tax liability based on the corrected information. If you owe more tax, interest may be charged from the original payment date. If you have overpaid, HMRC will arrange a refund or adjust your future payments.
When to Seek Professional Help
If the mistake involves complex issues such as capital gains, VAT, or you’re unsure how to amend, consider consulting an accountant or tax adviser. They can help ensure corrections are made properly and liaise with HMRC if needed.
Summary
In brief, you can usually amend your sole trader Self Assessment tax return online within 12 months of the filing deadline. After that, or if you filed on paper, contact HMRC directly. Keep clear records to support any corrections and act promptly to minimise interest or penalties.
Official reference: https://www.gov.uk/self-assessment-tax-returns. Always check the latest official guidance. Related forms: Browse our form category.
Important: This article provides general information. Government rules, forms and procedures can change, and this article may not reflect the latest updates. Check current GOV.UK guidance or the relevant authority before relying on it. ITG & Co. is independent and is not affiliated with a government department.