Yup - I'll join in voting for this will not work. Typically, the option to use any voucher will not appear when there is a partner flight (even if UA codeshare). This even extends to other forms of payments which aren't explicitly limited to UA metal flights (for example, UA gift certificates and travel bank funds).
I did once see the website appear to allow me to use it on an itinerary that had both UA/US flights, so i gave it a shot. It didn't ticket, and I got an email telling me I needed to call the day after making the reservation. When I did, it took me a while to convince the agent to allow me to just pay for the entire amount without using the TCV - agent was wanting to just cancel. So long story short, even if the website appears to allow you to use a TCV for a partner flight, in the end, you won't be able to.
Originally Posted by
Richard Chen
It likely won't work since UA & partners restrict availability to full fare classes with very low numbers at that.
This is not completely correct. Some airlines do indeed limit their lower class fares to be ticketed only on their stock, but that is wholeheartedly a partner decision - it is not UA and the partners - just the partner. Furthermore, this is only some partners, and for the most part, Asian-based carriers (minus ANA and AI that i have seen), NZ and SAA. The Euro-based carriers don't tend to have stock restrictions on lower fares, and I have certainly seen lower class fares show up on United.com on SAS, as well as LH (and Group) and AC.