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HMRC internal manual

Excise Assessments Interim Guidance

Evidence of fact: change in point of view

A change in viewpoint or interpretation of the same facts does not constitute new evidence and the time limits still apply from when the facts enabling you to make an assessment were first obtained.

It follows that you cannot use a re-interpretation of facts obtained more than one year earlier to argue that the assessment would still be within the one-year rule. You should bear this in mind when consulting other offices.