HMRC's second example at 3.3 of a function that is not a leaflet's is designed to obtain a discount on goods or services, which is a voucher in plain words. Section 8 puts coupons, coupon books, pools coupons and vouchers on the standard-rated side, and tokens with them. A money-off coupon printed as part of a genuine leaflet is a different matter: the leaflet stands or falls on the quarter rule, so a small coupon to be cut out of an otherwise zero-rated flyer does not spoil it, while a sheet that is mostly coupon is a sheet of coupons.
What decides it?
Whether the thing itself carries the value, or just mentions an offer.
Where does this come from?
HMRC VAT Notice 701/10, paragraph 3.3, HMRC's guidance on zero rating books and printed matter. See the notices we work from.
Some real jobs
A sheet of money-off coupons for a supermarket20%
Designed to obtain a discount, which HMRC names as not a leaflet's function.
A gift voucher with a face value20%
Vouchers and tokens are listed as standard-rated.
An A5 flyer advertising a sale, with a small coupon in one corner0%
Still a leaflet, as long as the part to be detached and returned is a quarter or less of the area.
