Originally Posted by
flyerCO
What 2 hour limit? Are you maybe thinking of applying a RUC/GUC?
My mistake, 3-hour limit. At some point, companion upgrades had to be requested at least 3 hours before departure. It seems that Delta removed the text from the website after the redesign (and it's been a bit longer since the last time a gate agent quoted the 3-hour rule) but you can still find it in the web archive:
https://web.archive.org/web/20170729...-upgrades.html
Both passengers must be ticketed, and upgrades must be requested at least three hours before the scheduled departure of the flight. Except as stated in this section, the rules governing complimentary Medallion Member upgrades also apply to companion upgrades.