Mixed class of services
 

I am trying to book a round trip award flight from ORD-BKK and seem like on the return flight most portion from BKK to NRT or HKG are only on economy class but the other portion to ORD would be business. If I book now and then business class opens up on the first portion. Will there be a fee if I request for the change? Also if I end up with economy class on the first portion, what my luggage allowance will be? Economy class allowance or business?

Thanks

Since you're booking this as a round trip you will have to pay the full business class price (in miles) and you can then waitlist for business. There will be no fee when you're confirmed.

If you're seated in economy at the time you check your luggage then you'll get the economy baggage allowance.

if booked as a mixed cabin award, perhaps depending on status and/or how soon the flight is, see award fee chart

if you have a mixed cabin ticket / award with multiple segments, the bag benefit is based on the highest ticketed cabin.