Article 9 Calculation of the payments on account

Where in the period of the year mentioned in paragraph (a), (b) or (c) of article 8 above a prescribed accounting period of the taxable person did not begin on the first day or did not end on the last day of a month, the reference period shall, for the purpose of article 8, be regarded as having comprised those prescribed accounting periods which related to the tax periods ending within the period of the year mentioned in paragraph (a), (b) or (c) of article 8 as appropriate to which references are shown in the certificate of registration issued to him.