The claim that United "does not allow" carry-on bags is a common misconception that applies specifically to their Basic Economy fare on domestic and short-haul international flights. If you book a Basic Economy ticket, you are strictly limited to one personal item (e.g., a backpack or purse) that fits under the seat in front of you; a full-sized carry-on for the overhead bin is prohibited. If you bring one to the gate, you will be charged the standard checked bag fee plus a $25 gate handling fee. However, all other United fare classes (Economy, Economy Plus, First, etc.) allow for one full-sized carry-on plus a personal item. Additionally, even on Basic Economy, certain passengers are exempt from this restriction, including MileagePlus Premier members, those with a qualifying United credit card, and Star Alliance Gold members, who all retain their full carry-on privileges regardless of the fare class.