Check in as soon as the 24-hour window opens. Checking in online right at the 24-hour window can put you first in line for the best seats, and also prevent you from being bumped by the airline.

United Airlines is changing how early you need to check-in for flights. Here's the new deadline Previously, the check-in cutoff for United Airlines was 30 minutes for domestic flights.

You'll have less time to check in for your flight once the new policy takes effect on June 3.

United Airlines is reportedly changing its policy. Flyers without checked luggage will have to check in 45 minute before their flight.