Originally Posted by NDNate

Bump. I'm in a similar predicament to the one described above. I'm a United 1K flying on a US-operated UA codeshare flight from CLT-SFO in a couple weeks. Could I upgrade this flight if I were to acquire a North America Space Positive upgrade from one of my US friends? I'd think that I could upgrade the flight, since it's on US metal, but it's a United ticket (016), so I don't know for sure.