[F190B.  Where relevant services are treated as supplied on or after 1st July 1997 by virtue of regulation 90 or 90A above, the supply shall be treated as taking place only to the extent covered by the lower of—U.K.

(a)the payment; and

(b)so much of the payment as is properly attributable to such part of the period covered by the payment as falls after 30th June 1997.]