Prospective
12(1)Sub-paragraph (2) applies where—U.K.
(a)an assessment has been notified to a person under paragraph 11, and
(b)it appears to the Commissioners that the amount which ought to have been assessed as due exceeds the amount that has already been assessed.
(2)The Commissioners may—
(a)on or before the last day on which the assessment under paragraph 11 could have been made, make a supplementary assessment of the amount of plastic packaging tax due from the person, and
(b)where such a supplementary assessment is made, notify the amount to that person.