How to Correct a Self Assessment Return After Filing as a Sole Trader

If you’ve submitted your Self Assessment tax return but later realise there’s an error or omission, it’s important to know how to make corrections properly. This guide explains the practical steps for sole traders in the UK to amend their Self Assessment return after filing.

When Can You Make Corrections?

You can generally amend your Self Assessment return up to 12 months after the original filing deadline for that tax year. For example, for the tax year ending 5 April 2023, the online filing deadline is 31 January 2024, so you have until 31 January 2025 to make changes.

If you spot a mistake within this period, you should correct it as soon as possible to avoid potential penalties or interest on any additional tax owed.

How to Amend Your Return

1. Online Amendments:
   If you filed your return online, you can log back into your HMRC online account and select the option to amend your submitted return. You can then update the relevant sections, such as income figures, expenses, or allowances.
2. Paper Amendments:
   If you submitted a paper return, you can send HMRC a corrected paper return. Include a note explaining the changes and clearly mark it as an amended return.
3. Contact HMRC if Needed:
   If you’re unsure how to proceed or the amendment is complex, you can contact HMRC for guidance. They may also advise you to write a letter detailing the correction.

Examples of Common Corrections

• You initially forgot to include some business income received after the filing date.
• You claimed incorrect expenses or omitted allowable costs.
• You made a mistake in your capital gains figures related to business asset sales.

Important Considerations

• Keep Records: Maintain clear documentation supporting any changes you make, such as invoices, receipts, or bank statements. This is important if HMRC queries your return.
• Additional Tax and Interest: If your correction means you owe more tax, paying it promptly will reduce interest charges. HMRC will calculate any interest due on late payments.
• Penalties: If errors are corrected within the allowed timeframe and you act promptly, penalties may be avoided or reduced. However, deliberate or careless errors can lead to penalties.
• Beyond 12 Months: If you need to correct a return after 12 months from the filing deadline, you should write to HMRC explaining the error. In some cases, you might need to make a formal appeal or wait for HMRC to contact you.

Summary

For sole traders, correcting a Self Assessment return after filing is straightforward if done within 12 months of the deadline. Use your online account to amend returns submitted digitally, or send a corrected paper return if applicable. Always keep supporting records and act promptly to minimise any tax, interest, or penalties due. When in doubt, contact HMRC directly for advice on your specific situation.

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.