Travelers who fail to follow the policy could be denied the option to check their bags or be forced to miss their flight.

U.S. travelers flying with United Airlines will have to check in to domestic flights a little earlier starting next week. That is, if they’re customers only taking carry-on

United Airlines is changing the amount of time travelers have to check in for a flight starting next month. Beginning June 3, those flying United will need to check in within 45 minutes of their flight for domestic flights - whether or not they have baggage.