Correct a locked Self Assessment tax return in FreeAgent

This article explains what to do if you realise that you made a mistake on a Self Assessment tax return after you’ve filed it to HMRC through FreeAgent.

Before you get started

Check with an accountant 

We strongly recommend that you check with an accountant before making any changes to a filed tax return in FreeAgent. If your accountant is set up as a user in your FreeAgent account, they might prefer to do this on your behalf.

If you’re not currently working with an accountant, take a look at our accountant directory. FreeAgent’s support team is not authorised by HMRC to provide advice on amending filed tax returns. 

If your accountant advises you to make corrections to your tax return in FreeAgent, please follow the steps outlined below. 

Check HMRC’s deadline for correcting mistakes on a filed tax return 

HMRC imposes a deadline for correcting any mistakes on a filed tax return. This deadline is one year after the online filing deadline of the tax return that you want to correct. For example, if you discover that you made a mistake on your 2020/2021 tax return, the deadline for correcting this will be 31st January 2023.

If you have filed both your 2020/2021 and your 2021/22 tax returns and you're still within the deadline for submitting amends for the earlier tax return (before 31st January 2023), you'll need to follow the instructions outlined below to unlock the most recent return before you can unlock the earlier one and correct it.

If the deadline for correcting the tax return you want to amend has passed, you won't be able to unlock or correct this tax return in FreeAgent and you should speak to your accountant instead. They will be able to advise whether you should make the corrections in the current tax year or if you should contact HMRC to explain the error and update the submitted return. 

1. Unlock the tax return

Navigate to the ‘Taxes’ tab at the top of the screen and select ‘Self Assessment’ from the drop-down menu.

Select the relevant user from the drop-down menu.

Select the relevant tax year from the list or from the ‘History’ drop-down menu to view the tax return.

Before you unlock your tax return, we strongly recommend you take a copy of the long ‘IR’ mark, which is displayed on the right-hand side of the screen, and save copies of your Self Assessment Return and Tax Calculation (SA302). To do this, select the blue 'Export' button at the top of any page of the return.

Select ‘Unlock return’ in the top-right. Please note that this button will only be visible if the tax return has been filed to HMRC using FreeAgent.

Select ‘Unlock return’ in the pop-up window to complete the process.

2. Make the necessary corrections

Edit the information in the tax return as required, keeping in mind your accountant’s advice and any guidance from HMRC. You can use the tabs at the top of the return to navigate between the different pages of your tax return.

3. Re-file your amended tax return to HMRC

Select the ‘Prepare to file online’ button.

Ask your accountant to review the changes you’ve made to your tax return. When you’re both happy that the amended tax return is ready to be filed to HMRC again, enter your Government Gateway ID and password, then select 'Submit Self Assessment'.