Hi everyone,

I've got some United miles that I'd like to use for a trip to New Zealand. I've never used my UA miles before for a partner flight, so this is all new to me. I noticed there's award space from my home airport to ICN (on Asiana) to AKL (on Air New Zealand). My question is this: if I book the award flights on United's website, but want to upgrade to the Skycouch on the Air New Zealand flight to/from AKL/ICN, can I pay for that separately through Air New Zealand? If so, would I have to call into their reservations number to do so?

Thanks!