However, the procedure for getting the United Airlines seat upgrade isn't as simple as it was. There are a variety of ways that passengers are eligible for upgrades, in addition to the fact that the carrier has regulations that determine the first to receive upgrades. To upgrade your online reservation, log in with your MileagePlus account, then go to the reservation you have already made. United Upgrade to First Class option can help gain several benefits. https://bit.ly/3r3epPC