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How to Correct Mistakes in a Submitted Tax Return

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How to Correct Mistakes in a Submitted Tax Return

How to Correct Mistakes in a Submitted Tax Return

At Payless Accountant, we understand the stress that tax errors bring, and we’re here to guide you through the process of fixing them effectively.

Common Tax Return Mistakes

Before learning how to correct them, it’s worth knowing the most common errors people make, such as:

  • Incorrect personal details (name, address, NI or UTR number).

  • Misreporting income from self-employment, investments, or freelance work.

  • Claiming the wrong tax reliefs or allowances.

  • Forgetting to include certain expenses or pension contributions.

  • Calculation errors in taxable income or refunds.

These errors might seem small, but they can lead to penalties, interest charges, or even a tax investigation if left uncorrected.

How to Correct Your Tax Return

1. Check the Deadline

HMRC allows you to amend your Self Assessment tax return up to 12 months after the original filing deadline. For example, if you filed for the 2023/24 tax year, you have until 31 January 2026 to make corrections.

2. Amend Online (If You Filed Digitally)

  • Log in to your HMRC Online Services account.

  • Select “Tax Return” and choose the year you want to amend.

  • Make the necessary corrections and resubmit.

  • Always keep confirmation copies for your records.

3. Amend a Paper Return

If you filed a paper return, you’ll need to download the correct tax return form for the year, mark it as “amended,” and send it back to HMRC.

4. Write to HMRC (If Deadline Has Passed)

If the 12-month correction window has closed, you can still write to HMRC to explain the error. They may adjust your bill if you’ve paid too much tax, or they may recalculate what you owe.

5. Correcting Refunds & Overpayments

If your mistake means you’ve overpaid tax, you can usually claim a refund within four years of the tax year in question. HMRC will process your claim once they verify the correction.

Why Professional Help Matters

Correcting tax mistakes isn’t just about filling in the right figures — it’s about understanding how those changes affect your overall financial situation. With expert guidance from Payless Accountant, you can:

  • Avoid penalties and interest charges.

  • Maximise legitimate tax reliefs.

  • Get peace of mind knowing your records are accurate.

Final Thoughts

Mistakes in tax returns happen more often than you might think, but they don’t have to cause unnecessary stress. By following the right correction process — or working with a trusted accountant — you can ensure your tax affairs remain compliant and penalty-free.

At Payless Accountant, we specialise in helping individuals, freelancers, and businesses manage their tax responsibilities with ease. If you’ve made an error in your return, reach out today — we’ll help you set it right.