A transaction handler receives, for forwarding to a sponsor account's issuer, a coupon authorization request message from a merchant's acquirer that identifies the sponsor account and a coupon for an item being purchased by a consumer in a transaction with the merchant. The issuer determines eligibility of the coupon for use by the consumer, and sends an authorization response message to the merchant via its acquirer and the transaction handler for the application of a corresponding discount for the item when the coupon is eligible. One or more coupon eligibilities for the purchase of the item by the consumer from the merchant can be derived from comparisons of the transaction to predetermined times, geographies, jurisdictions, sets of merchants, and/or the number of times that coupons have been used in other transactions. The transaction handler can further process the transaction for authorization the consumer's account to pay of the transaction.