My recent experience - late October 2017 BKK (NH with UA code) -> NRT -> UA
Unable to OLCI at T-24, T-12, T-6 with message ""Online Check-in service is not available. Please check in at the airport on the day of your departure. (E_C02P05_H630)". Just to be sure, I tried the mobile app too (it is a sub-optimal app and appears to screenscrape the NH web), and tried using both UA and NH PNRs (NH recently introduced ability to accept UA PNRs). No success. UA segment itself was within T-24 as well.
Was able to change seat during OLCI process though. The "view reservation" still reported old seat but seat change stuck through the counter check-in.
Gave up at T-6 since BKK check-in counters open at 7pm for the 2 evening flights.
My lack of success with OLCI, contrary to previous posters' reports, may be related to either:
a) Y ticket, OR
b) I was SSSSed on UA segment this one time, OR
c) the new travel checks for inbound US flights that started Oct 26, OR
d) it just doesn't work for some
Probably (b) but reviewing past notes that I've kept, I have never been able to OLCI, not even at T-12 and below, and all this with no past SSSS experience on the UA segment. I fly several of these same BKK-US flights a year on NH/UA, always in Y, and have only been successful when flight is the BKK flight is coded NH.
The reverse journey, UA->NH has not been a problem. Check-in on UA mobile app and I get both boarding passes
Last edited by tide; Oct 30, 2017 at 11:12 am
Reason: added UA->NH experineces