A jeopardy amendment can be made to a taxpayer’s Self-Assessment return as part of an S9A general enquiry. A jeopardy amendment should only be made where an HMRC officer believes there is an imminent risk of a loss of tax to the Crown unless the assessment is amended at once. i.e., the tax due is in jeopardy. For example, the officer may become aware that the taxpayer has plans to leave the country or is disposing of assets.

A jeopardy amendment may be made where:

and,

HMRC manuals are clear that this is not a routine procedure. HMRC should only make a jeopardy amendment where there is a real risk of the loss of substantial amounts of tax.

Source:HM Revenue & Customs| 10-10-2022