If you make a mistake on your Company Tax Return form, supporting documentation or claim and you don't discover the mistake until after you've filed your return, you can correct it by amending your return.
You can also amend your return if your circumstances change. For example, if you originally included estimated figures on your return and now have the actual figures, or you want to amend a claim you made in the original return or make a new claim.
This guide shows you how to amend a Company Tax Return. It also tells you the time limits for amending your return and in what circumstances HM Revenue & Customs (HMRC) can correct or amend your return.
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You might discover that you've made a mistake, or that you need to change your Company Tax Return form, or supporting documents, after you've filed them.
This is known as 'amending your Company Tax Return'.
You might need to amend your return if, for example:
You can amend your Company Tax Return at any time up to 12 months after your filing deadline (known to HMRC as your 'filing date' or 'statutory filing date'). Your filing deadline is usually 12 months after the end of your Corporation Tax accounting period. So you can usually make an amendment to a return up to 24 months after the end of your accounting period.
So if your accounting period is from 1 April 2008 to 31 March 2009:
The deadline for amending your Company Tax Return is not extended if you file late. So if you file your return more than 12 months late, you won't be able to make an amendment to it.
If you find an error on your Company Tax Return but you're too late to amend it, you must still tell HMRC immediately. If you don't, you may be liable to a penalty if there's more Corporation Tax to pay. If you've paid too much Corporation Tax as a result of the mistake, you may be able to get this back. This is known to HMRC as 'overpayment relief'. If you think this applies to your company or organisation you should contact your Corporation Tax Office immediately.
Corporation Tax deadlines and requirements
Find your Corporation Tax Office
You can amend your return online, or you can write to your Corporation Tax Office with details of the amendment you want to make.
Find out how to amend your Company Tax Return online
Find your Corporation Tax Office
You can make a claim to reduce the amount of Corporation Tax you have to pay. Some claims reduce the taxable profit you'll have to pay Corporation Tax on; other claims reduce your tax bill. So for instance a claim for:
You can make most claims when you fill in your Company Tax Return. If you forget to make a claim, or decide to claim after you have filed your return, you can simply amend your return in the usual way to include the claim.
For information on how to do this, see the section above on amending your Company Tax Return.
You are not able to claim overpayment relief if you forget to claim another relief or allowance in your return, or want to make a claim after the deadline for amending your return has passed.
Some claims have long time limits and so they can be made after the deadline for amending your return has passed. You can make these claims separately from your return, by writing to your Corporation Tax Office.
If you want to amend a claim that you've made separately from your return, you should write to HMRC explaining what you want to amend. The deadline for doing this is normally 12 months after you've made the claim.
Find out more about Corporation Tax claims and elections
Find your Corporation Tax Office
HMRC can change obvious mistakes or minor errors in your Company Tax Return, supporting documents, claims or amendments. This is known as making a 'correction'. For example HMRC can correct arithmetical errors or failing to put an 'X' in a relevant box.
HMRC can make a correction at any time up to nine months after you've filed your return, amendment or claim. A penalty may be considered if, after correction, HMRC discovers that the inaccuracy on your Company Tax Return, amendment or claim was due to carelessness or was deliberate.
If HMRC thinks there's something seriously wrong with the figures in your return, supporting documentation or other information you've submitted, a correction will not be enough. Instead, HMRC will make an 'enquiry' or carry out a compliance check into your return, amendment or claim.
You can still amend your Company Tax Return after HMRC has started an enquiry or check, within the normal time limits. But they'll carry on with the enquiry until they're satisfied that they know the correct position. You may also have to amend your return at the end of an enquiry if HMRC finds that it was incorrect, or they may amend it for you.
HMRC compliance checks and enquiries for Corporation Tax
