Sch 10B para 4
(1) A voucher is a single purpose voucher if, at the time it is issued, the following are known— (a) the place of supply of the relevant goods or services, and (b) that any supply of relevant goods or services falls into a single supply category (and what that supply category is). (2) The supply categories are— (a) supplies chargeable at the rate in force under section 2(1) (standard rate), (b) supplies chargeable at the rate in force under section 29A (reduced rate), (c) zero-rated supplies, and (d) exempt supplies and other supplies that are not taxable supplies. (3) For the purposes of this paragraph, assume that the supply of relevant goods or services is the provision of relevant goods or services for which the voucher may be accepted as consideration (rather than the supply of relevant goods or services treated as made on the issue or transfer of the voucher).