Paragraph 11 I1I2

For the purposes of a penalty under this Schedule references to a liability to tax which would have been shown in a return are references to the amount which, if a complete and accurate return had been delivered on the due date, would have been shown to be due or payable by the taxpayer in respect of the tax concerned for the period to which the return relates.

In the case of a penalty which is assessed at a time before the person makes the return to which the penalty relates, HMRC may either—

If the person subsequently makes a return, the penalty must be re-assessed by reference to the amount of tax shown to be due and payable in that return (but subject to any amendments or corrections to the return).