On United Airlines, the fare basis code for Basic Economy typically begins with the letter "N". This is the airline's most restrictive fare class, designed to compete with low-cost carriers. When you see an "N" class ticket, it means you will not be able to bring a full-sized carry-on bag (only a personal item that fits under the seat), you cannot select your seat for free, and you will be in the last boarding group. Additionally, "N" class tickets are generally non-refundable and non-changeable, though you may be able to "add" economy benefits for a fee later. It is important to check the "Fare Class" or "Booking Code" on your receipt or in the app, as other letters like Y, B, M, or H represent full-fare economy, which comes with much more flexibility and standard amenities.