Originally Posted by
IggySD
UA allows one way awards and I think US does as well so it may be best to go outbound on one carrier and inbound on the other if you have issues with availability not matching up. The downside is you lose the opportunity for a stop over and potentially double any change fees.
UA one ways are allowed no problem. US, not really. From the Dividend Miles page on US:
5.All award tickets must be issued and ticketed for roundtrip travel. One-way ticketing is permitted but will be issued at a roundtrip value.