How to Amend Your Self-Assessment Tax Return After Filing

You can amend the tax return which is already filed to HMRC in case you realised you had made a mistake in the tax return filed. This can be done through simple process devised by HMRC. How you do this depends upon the HMRC’s time limit and how you had originally filed it.

Is there a Deadline for Making Changes?

Yes. There is a specific time limit devised by HMRC till when you can amend your tax return. The deadline is within 12 months of the self-assessment deadline. This update/amendment can be done through either online or by sending another paper return.

What happens if you missed the deadline?

If you missed the deadline to amend tax return then you will need to write to HMRC, you won’t be able to amend through online.

This also applies if you want to amend the tax return from an earlier tax year.

You will also need to write to HMRC a letter mentioning unreported income in your tax return and claiming overpayment relief (in case if you think you have overpaid tax)

Overpayment relief can be claimed up to 4 years after the end of the tax year it relates to.

What to include in the writing?

If these information aren’t included in your letter your claim will be rejected. You will also need to prove that you have already paid tax for the relevant tax yar through self-assessment process.

You also need to outline how you wish to receive your refund (i.e. bank transfer, cheque, etc.) and the relevant details HMRC will need to pay you.

How do I make changes to my Tax Return?

The way you make changes to a previously filed tax return depends upon the way how you initially submitted it. Uk taxpayers could use either option for submitting tax returns.

• On paper
• By online (digital self-assessment return)

Paper Returns

The deadline for submitting paper tax returns is 31 Oct after the end of the relevant tax year.

If after this you realised that you have made a mistake, you will have to download the whole new tax return and then correct the necessary pages ,write amendment at the top of the corrected pages and send this new tax return to the same old address in which you had sent previous self-assessment tax return by including your name and your unique taxpayer number(This will be on the previous tax returns or letters from HMRC).

Online Returns

The deadline for submitting online tax returns is following 31 Jan after the end of relevant tax year. If after this you realised that you have made a mistake, you can still amend your tax return. For amending you can follow the steps provided by HMRC in HMRC guidelines.

However, you must wait 72 hours after filing before amending your online filed tax return.

What if you have filed tax returns through commercial software?

If you have filed your tax return through commercial software, then you will have to contact your software provider for help correcting your tax return. In case your software provider is not able to make corrections, you would have to contact HMRC.

Will I need to pay more tax if I change my tax return?

This depends upon what corrections are you making. If you are making amendment for the forgotten income, your tax bill might go up. But this also means that you are being proactive about correcting your mistake and so you are likely to avoid any penalties that you can get if HMRC discovers your undeclared income themselves.

But if your amended return gives HMRC new information which helps you claim a refund, then you’ll be due a nice cheque in the mail, or a reduction of your next tax bill.

Changes to your bill

Your tax bill would be updated within 3 days of your tax return update. Within 3 days, your statement within your government gateway account will show the difference amount from the old tax bill enabling you to see whether we owe more or less tax and whether we are owed any refund. It will also include any interest of the differential amount i.e. either interest will increase the tax payable or increase our refund amount.

If you are owed tax

You may be able to claim a tax refund. However, you may not get a refund if you have tax due in the next 45 days (for example for a payment on account). Instead, the money will be deducted from the tax you owe.

If you have already claimed tax refund, the status of your refund may show as pending in your online tax account which means that refund has been initiated/created but still needs to be approved and paid.

If you need to pay more tax

If it occurs that after the amendment you need to pay more tax, then the updated bill on your statement within government gateway account will show the deadline for paying as well as any effect that this will make on payments on account you need to make.

If you sent an updated paper return

You will be sent an updated bill by HMRC. You can check when you can expect a reply from HMRC. This can be done through,

 In case of refund, HMRC will pay any refund directly into your bank account if your bank details are included in your tax return.

Conclusion

The article outlines the process for correcting mistakes on your self-assessment tax return, including how to amend it online within 12 months of the filing deadline. If the correction reduces your tax bill, you may receive a refund. It's important to make these corrections as soon as possible to avoid penalties or interest charges.