$200 to $500
To switch to that flight, Delta would charge a $200 change fee, plus another $125 for the fare difference ($375 minus $250). So the change you want to make would cost $325 total. Change Fees. Based on the fare rules, you may have to pay a service fee and/or a difference in fare. For travel within the 50 United States, Canada, Puerto Rico and the U.S. Virgin Islands, the fee is $200 for Delta-marketed flights. 1 You can make changes to your flight time within three hours of departure for a $50 fee. 2  For example, if you have a 10 a.m. flight, and would like to leave at 7 a.m. -- and there is room on the flight -- you can change to the earlier flight any time after 4 a.m. for the $50 fee. For travel outside the United States, Canada, Puerto Rico, and the U.S. Virgin Islands, the change fee for Delta-marketed flights is typically $200 to $500, but can vary based on location and type of fare. Changes are usually permitted only to the return portion of an international itinerary. The cost to change a flight depends greatly on the airline that you have purchased your ticket from. Airlines have “penalty fees” that can range from $0 to $400.00 (yowza!) to make a change to your ticket. For domestic flights, most airlines charge around $200. But the penalty is not the whole story. United Airlines. Same-day change fees on United Airlines cost passengers $75. For changes to a ticket that extend beyond 24 hours of the original flight time, passengers must pay a $150 flight change fee for domestic flights, and $250 for international.
https://www.cheapair.com/blog/travel-tips/ask-cheapair-how-much-does-it-cost-to-change-an-airline-ticket/ http://www.delta.com/content/www/en_US/traveling-with-us/ticket-changes-refunds/ticket-changes.html http://traveltips.usatoday.com/change-delta-nonrefundable-ticket-61012.html http://www.delta.com/content/www/en_US/traveling-with-us/ticket-changes-refunds/ticket-changes.html https://www.cheapair.com/blog/travel-tips/ask-cheapair-how-much-does-it-cost-to-change-an-airline-ticket/ http://www.ifly.com/airline-change-fees
delta how much to change flight date