13There is no supplementary charge under this Schedule on a supply of goods within paragraph 2 if—
(a)the only relevant condition met is condition D,
(b)the VAT invoice—
(i)relates to a supply of goods made under a hire-purchase, conditional sale or credit sale agreement,
(ii)forms part of that agreement, and
(iii)is issued in accordance with normal commercial practice in relation to a supply made under such an agreement, and
(c)the basic time of supply of the goods is intended and expected to be within 6 months of the date of the VAT invoice which relates to the supply.