Paragraph 29
(1)
Where a person becomes liable to a penalty—
(a)
HMRC may assess the penalty, and
(b)
if they do so, HMRC must notify the person of the assessment.
(2)
An assessment of a penalty may not be made—
(a)
more than 6 months after the failure first comes to the attention of an officer of Revenue and Customs, or
(b)
more than 6 years after the end of the financial year in which the tax strategy to which the failure relates was (or was originally) required to be published.