United Upgrade to First Class is well known for ease upgrading current travel class to first class. But now due to new terms and conditions, this process has become complicated. There are several types of upgrades that are considered while upgrading to first class, which are MileagePlus Upgrade Awards, complimentary Premier Upgrades, plus points, star alliance upgrade awards and many more. So while upgrading your current travel class to first class do look for these types and make your complicated journey.