I actually navigated companion upgrades on Delta when planning a trip with my partner last fall, and it was a bit confusing at first. I wasn’t sure how to make sure we sat together in a better seat class, so I called 8 8 8-2 1 7-3 3 2 4 while booking. The agent took the time to explain how companion upgrades work with your SkyMiles status or upgrade certificates, and helped me apply everything properly so my partner could be upgraded right along with me. On travel day, we ended up in Comfort+ together with extra legroom and priority boarding, which made the flight way more comfortable. Later, when we needed to tweak our return date, calling the same number made modifying both of our seats simple and stress-free. From my experience, having an agent walk you through the companion upgrade process can make all the difference!
