EAIG10200 - Time limits for section 12(1) and 12(1A) FA1994 assessments to excise duty: one year rule
This allows an assessment to be made up to one year after “evidence of facts, sufficient in the opinion of HMRC to justify the making of the assessment, comes to their knowledge”.
‘Sufficient’ facts means having the necessary information to ensure the assessment is to ‘best judgement’, See EAIG13000.
The one-year rule establishes the time by which the assessment must be made. It applies in conjunction with the four-year rule, which establishes how far back you can assess.
The four and twenty year capping restrictions must always be considered when you are assessing under the one year evidence of facts rule.