delta flight change fee and refund

Based on the fare rules, you may have to pay a service fee and/or a difference in fare if you want to change your flight. For travel within the 50 United States, the fee is $150 for Delta airlines flights.

Refundable Tickets
You may change your flight without paying a change fee provided all fare and ticket rules are met and seats are available. If you do not wish to reschedule your travel, you can apply for a refund.

delta airlines same-day confirmed option allows you to change your flight time on the same day of travel for a fee of $50.
The delta airlines policies regarding ticket changes for nonrefundable tickets vary. Bulk fare or tour fare tickets issued through certain third-party websites and travel agents are not eligible for any changes. Check Same-day Travel Changes to review your options if you only want to change the time you depart or request an upgrade.
For international flight, the change fee is typically $250, but can vary based on location and type of fare. Changes are usually permitted only to the return portion of an international itinerary.

External Tickets
An additional charge applies if you would like us to change a ticket that we didn't issue. This charge applies to any ticket issued in the United States or Canada by anyone other than us, such as:

A traditional travel agency.
An online travel agency.
Another airline, including SkyTeam and codeshare partners.
The external ticket handling charge does not apply to:

Tickets originally issued by us—Reservation Sales, ticket office, or delta.com.
Involuntary changes like cancellations, delays, or schedule changes.
Tickets issued with military or government fares.
Customers completing a SkyMiles upgrade.
Same-day Confirmed Travel.
The $50 external ticket handling charge is:

Waived if the change can be completed here at delta.com.
Applied for tickets changed through Reservations Sales.
Applied for tickets changed at one of our Ticket Office Locations.