Changing your Self Assessment Tax Return

If you have missed the deadline or if you need to make a change to your return for any other tax year you will need to write to HMRC.

Your bill will be updated based on what you report therefore the accuracy of the information is imperetive. You may have to pay more tax or be able to claim a refund.

If you need to change your return

The following dates are when you will need to make changes to your tax return if you’ve made a mistake or received additional notable information that will affect your return. You’ll need to make your changes by:

·   31 January 2019 for the 2016 to 2017 tax year

·   31 January 2020 for the 2017 to 2018 tax year

Updating your tax return

Depending on how you filed your tax return very much depends on how you can update it.

Online tax returns – This is quite straight forward and self explanatory

·   You will need to log in to your online HMRC account

·   From ‘Your tax account’, choose ’Self Assessment account’ (if you do not see this, skip this step)

·   Choose ‘More Self Assessment details’

·   Choose ‘At a glance’ from the left-hand menu

·   Choose ‘Tax return options’

·   Choose the tax year for the return you want to amend

·   Go into the tax return, make the corrections and file it again

Paper tax returns

You will need to download a new Tax Return and send HMRC the corrected pages. You must write ‘amendment’ on each page, and include your name and Unique Taxpayer Reference (UTR) - this is on previous tax returns or letters from HMRC.

Check your Self Assessment paperwork for the address. If you cannot find this, send your corrections to the address for general Self-assessment enquiries.

HMRC approved commercial software

Contact the software provider for help correcting your tax return. Failing this you can contact HMRC if your software is not able to make corrections.

In writing

You can write to HMRC if you need to make a change to your tax return from the 2015 to 2016 tax year or earlier.

Include in your letter:

·   The tax year you’re correcting

·   Why you think you’ve paid too much or little tax

·   How much you think you’ve over or underpaid

You can claim a refund up to 4 years after the end of the tax year it relates to. If you’re making a claim, also include in your letter:

·   That you’re making a claim for ‘overpayment relief’

·   Proof that you’d paid tax through self assessment for the relevant period

·   How you want to be repaid

·   That you have not previously tried to claim back this refund

·   A signed declaration saying that the details you’ve given are correct and complete to the best of your knowledge

Changes to your bill

You’ll see your amended bill straight away if you updated your tax return online. Within 3 days, your statement will also show:

·   The difference from the old one, so you can see whether you owe more or less tax

·   Any interest

To view this you need to log into your HMRC account and choose ‘View statements’ from the left-hand menu.

What if I’m owed tax?

To claim a refund, go to ‘Request a repayment’ from the left-hand menu within your HMRC online account. Allow 4 weeks for your refund to be sent to your bank account.

You may not get a refund if you have tax due in the next 35 days (for example for a payment on account). Instead, the money will be deducted from the tax you owe.

What if I owe more tax?

Your updated bill will also show:

·   The deadline for paying

·   The effect on any payments on account you need to make

Paper returns

HMRC will send you an updated bill within 4 weeks. They’ll also pay any refund directly into your bank account, as long as you included your bank details on tax return.