The UK Rules
'Follow the Regulations'

Self Assessment Tax Return Corrections

There may be circumstances when you need to change a tax return after you filed it. This page explains how to make Self Assessment tax return corrections if you make a mistake.

SELF ASSESSMENT CORRECTIONS: There are deadlines for correcting a Self Assessment tax return:

You must write to HM Revenue and Customs if you miss any of these deadlines. The same process applies if you need to make tax return corrections for any earlier tax years than these.

HM Revenue and Customs update your bill based on what changes and errors you report.

In some cases you will have to pay more tax and in others you may qualify for a tax refund (rebate) instead.

How Can You Update a Tax Return?

The method for updating tax returns will depend on how it got filed in the first place. Follow these steps to update a tax return online or make changes to the paper version.

7 Steps to Update a Tax Return Online

  1. Log in to your HM Revenue and Customs Government Gateway online account.
  2. Select 'Self Assessment account' from 'Your tax account' (skip this section if it does not show).
  3. The next step is to choose 'More Self Assessment details'.
  4. Then select 'At a glance' showing in the left-hand menu.
  5. Choose 'Tax return options'.
  6. You then need to select the correct tax year for the tax return that you want to amend.
  7. Step seven is to going into the relevant tax return and making the corrections. File it once more after you make the changes.

Update a Paper Tax Return

You can use the Self Assessment forms and helpsheets to download a new tax return. Send the corrected pages to HMRC Self Assessment general enquiries address.

You should write the word 'amendment' on every page that you corrected. Remember to include your name and Unique Taxpayer Reference as well. Your UTR shows on any previous tax returns or letters that you received from HMRC.

Commercial Software for Self Assessment Tax Returns

It is best to contact the provider if you use commercial software for Self Assessment tax returns. They should be able to help you correct your tax return. Contact HMRC if they are unable to make the changes for you.

Changes to Tax Return 2014 (or before)

You need to write to HMRC to make changes to a tax return for the 2014 to 2015 tax year or earlier. Remember to include the following information in the letter:

  1. The specific tax year that you want to correct.
  2. The reason why you believe you paid either too much or too little tax.
  3. The amount that you think you overpaid or underpaid.

You can only claim your tax refund up to 4 years after the end of the tax year that it relates to. In this case you must include this extra information in your letter to HMRC:

Amended Changes Showing on a Tax Bill

Updating a tax return online means you see the amended changes to your bill straight away. It then takes around 3 working days for your statement to show:

Note: Choose 'View statements' from the left-hand menu after logging in to your account to view the changes.

How to Claim a Tax Rebate Online

Select 'Request a repayment' from the left menu inside your HMRC online account to claim a refund. But, it may take up to 4 weeks for a tax rebate to show up in your bank account.

Note: The refund may not show if you have tax due in the next 35 days (e.g. payment on account). The money gets deducted from the tax you owe instead.

If More Tax is Owed

In cases where more tax is due the updated bill will also show:

  1. The deadline for the payment.
  2. The effect it may have on any 'payments on account' and what you need to do.
  3. Whether you sent an updated paper tax return.

HM Revenue and Customs send the updated bill within 4 weeks and pay any refund into your bank account. This is providing you remembered to include your bank details on the tax return.

How to Make Self Assessment Tax Return Corrections after Filing in the United Kingdom