I am interested in spending 25,000 NH miles to upgrade from economy to business. My ticket is an upgradable “G” class fare and there is availability in the “I” fare class bucket.
As I read it, the ANA website says “ANA International Upgrade Award” on a segment can be made up to 24 hours before the departure time of that segment:
Application Period (Deadline)
From 355 days prior to the departure date until 24 hours prior to the departure of the relevant flight.
For comparison, here is the Japanese equivalent:
お申し込み期間（期限）
ご搭乗日の355日前からご搭乗便出発時刻の24時間前までお申し込みになれます。
I fly
outbound within 24 hours, and am interested in upgrading my
return flight next week.
Nevertheless, I was denied for the upgrade, even though there is I availability, and my ticket is an upgradable “G” class fare.
The reason given was that it is impossible to upgrade a flight at any point after “24 hours before the first segment.” There was a bit of a language barrier with the Japanese representative, so I may have misunderstood.
Is this a known fact, or was there a misunderstanding?