Taxes Management Act 1970 section 12ZN

Amendment of return by taxpayer during enquiry

Section 12ZN allows a taxpayer to amend their tax return even while HMRC is conducting an enquiry into that return, and explains how such amendments are treated.

• A taxpayer may amend their tax return while an HMRC enquiry into that return is ongoing.
• Any amendment made during an enquiry does not restrict HMRC's power to amend the return when they issue their closure notice at the end of the enquiry.
• If HMRC's closure notice states that no amendment is needed, any amendment the taxpayer made during the enquiry takes effect as normal.
• If HMRC's closure notice includes amendments to the return, HMRC's amendments take priority and the taxpayer's earlier amendment during the enquiry only stands to the extent it is not overridden.

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