Taxes Management Act 1970 section 9B

Amendment of return by taxpayer during enquiry

Section 9B deals with what happens when a taxpayer amends their self-assessment tax return at a time when HMRC is already conducting an enquiry into that return.

• A taxpayer may amend their personal or trustee return during an HMRC enquiry, but the amendment does not restrict the scope of that enquiry
• Any change to the tax payable figure in the self-assessment is suspended and does not take effect while the enquiry remains in progress on related matters
• If the HMRC officer addresses the amendment in a partial or final closure notice — either incorporating it or rejecting it as incorrect — the amendment does not take effect separately
• If the officer does not address the amendment in a closure notice, it takes effect when a partial closure notice covering the relevant matters is issued, or failing that, when the final closure notice is issued