premium voucher; shopping coupon
A voucher sold at a discount or with added value, often issued by local governments as an economic stimulus measure to boost consumer spending.
The premium vouchers issued by the city sold out immediately.
I used the premium vouchers to shop at local stores.
Regional promotion coupons, a similar economic stimulus tool, but プレミアム商品券 specifically emphasizes the premium (bonus) value.
Compound of プレミアム (premium, from English) + 商品券 (shopping voucher). The term gained currency in Japan as a name for government-issued stimulus vouchers.