Korean Air’s deferred revenue tied to unredeemed frequent flyer miles reached ₩3.1199 trillion, approximately $2.3 billion, at the end of the first half of this year, the Ministry of Land, Infrastructure and Transport said. The balance exceeded ₩3 trillion for the first time, rising 9.7% from ₩2.8 trillion at the end of last year, or ₩275.4 billion. Deferred mileage revenue represents the accounting value of services airlines are obligated to provide in the future against unused customer miles. Asiana Airlines had ₩936.1 billion in related deferred revenue.