19(1)For the purposes of this Schedule, in relation to a listed supply, “the basic time of supply” is the end of the period to which the VAT invoice or payment mentioned in paragraph 18(1) relates, except as provided in sub-paragraphs (2) and (4).U.K.
(2)Where the person making the supply issues an invoice—
(a)in respect of part of the listed supply to which the VAT invoice or payment mentioned in paragraph 18(1) relates, and
(b)for a period (a “billing period”) ending before the end of the period to which that VAT invoice or payment relates,
“the basic time of supply”, in relation to that part of the supply, is the end of the billing period.
(3)For the purposes of sub-paragraph (2) the listed supply (and the consideration for the supply) must be apportioned between periods on a just and reasonable basis.
(4)Where a listed supply is treated as taking place by virtue of—
(a)the issue by the person making the supply of a VAT invoice relating to a premium for the grant of a tenancy or lease, or
(b)the receipt by the person making the supply of such a premium,
“the basic time of supply” is the date of the grant of the tenancy or lease.