gift certificate; shopping voucher
A certificate or voucher that can be used like money for purchases, often at a particular store, department store, or group of affiliated shops.
I received department-store gift certificates for my birthday.
This gift certificate can be used at participating stores nationwide.
I gave my friend a gift certificate for their birthday.
I did my shopping at the department store using a gift certificate.
I won a gift certificate in the lottery.
I paid at the register with a gift certificate.