Through March 31, Japan Airlines is discounting mileage upgrade requirements—and offering double miles for the flight, depending on fare purchased. For example, a round-trip L.A.–Tokyo upgrade drops from 50,000 to 30,000 miles.

The Fine Print: Valid to and from Japan except for Hawaii–Japan, which is not eligible. Y, B, K and Q classes only. Code-share flights operated by other airlines are not eligible. Some one-way upgrades require round-trip mileage. Registration required prior to departure—promo code 52D. To book: call (800) 525-6453.