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Further information, feedback and correcting tax returns (part 4)

Published 1 September 2025

Read the other parts of these guidelines in conjunction with this part, if you have not already.

Further Information

These guidelines do not change HMRC’s approach to estimated or provisional figures. Further information:

Estimated or provisional figures for Corporation Tax returns

Estimated or provisional figures for Income Tax returns

Use of estimation for completing VAT returns

Feedback

You can contact the Guidelines for Compliance (GfC) team about the style and content of these guidelines, but the GfC team is unable to answer technical questions or to give an opinion on open compliance checks. Make sure you include the Guidelines for Compliance reference number, GfC13, in the subject line. Contact us at this email address ccgguidelinesforcompliance@hmrc.gov.uk.

Read about the risks of corresponding by email. We will not deal with you by email unless you tell us you accept the risks of doing so.

Correcting tax returns

If you no longer think a tax return, lodgement, or similar document you have previously sent to HMRC is correct and complete, then take all relevant steps to correct it. We’ve included information on how to correct some common documents in the following section. HMRC’s guidance will help you understand how to contact us for other documents. You can speak to your Customer Compliance Manager (CCM) if you have one. If you’re contacting HMRC about correcting a tax return after reading these guidelines, include the reference GfC13.

Income Tax and Corporation Tax returns

You can usually amend your tax return within 12 months of the statutory filing date. If you can no longer amend your tax return, then contact the Mid-sized Business customer support team, or your CCM if you have one.

Customers who have underpaid tax, including individuals and small businesses, can make a voluntary disclosure.

Use the digital disclosure service to tell us about underpaid:

• Income Tax
• Capital Gains Tax
• Inheritance Tax
• Corporation Tax
• National Insurance contributions
• Annual Tax for Enveloped Dwellings (ATED)

VAT returns

To correct a submitted VAT return, follow the error correction notice process outlined in How to correct VAT errors and make adjustments or claims (VAT Notice 700/45).

You can also use the VAT652 form to tell HMRC about errors in your VAT return.

When correcting a VAT return because of the information in these guidelines, include the Guidelines for Compliance reference number GfC13 in the ‘reason for error’ box.

PAYE and National Insurance contributions errors

If you identify an error in your Real Time Information (RTI) you sent to HMRC you can correct this by either:

• amending your RTI records — more information on how to do this is included in Fix problems with running payroll
• making a voluntary disclosure to HMRC, explaining the errors and calculating the tax due

If you are making a voluntary disclosure after reading these guidelines, include the Guidelines for Compliance reference number GfC13 as part of your disclosure.

P11D errors

If a P11D has been submitted, then an amended P11D should be filed with HMRC. You will also need to amend your P11D(b) to report any additional Class 1A National Insurance contributions. You must make any amendments online using the forms which can be found at Expenses and benefits for employers.

If a P11D was not submitted, then you should submit one as soon as possible. In addition, if you’ve not submitted a P11D(b), you should submit a P11D(b) at the same time. If you have already submitted a P11D(b) then you should amend this to report any additional Class 1A National Insurance contributions.

Alternatively, you can make a voluntary disclosure.

Employer liabilities for inbound foreign nationals on assignment to the UK

Employers disclosing inaccuracies for inbound foreign nationals on assignment to the UK should email the full disclosure to: internationaleddisclosures@hmrc.gov.uk.

Other Employer issues

Employers without another route to make a disclosure can contact the following address:

ISBC, Campaigns and Projects
HM Revenue and Customs
BX9 1QZ
United Kingdom