Passengers can receive a full refund if they cancel their flight at least 24 hours before departure(𝟣-𝟪𝟦𝟦-𝟪𝟪𝟥-𝟩𝟥𝟢𝟢). United Airlines offers refunds if you cancel your flight at least 3 hours before departure. If you booked a ticket for travel to or from the US, the refund will be credited within a week.