If you've already booked your trip and you're wondering how to add your SkyMiles number to an existing reservation, note that you can do this after the fact by accessing the “My Trips” tab on Delta's website.

Yes, you can add your Delta SkyMiles number to an existing booking, and it’s a very common and recommended practice to ensure you earn miles and Medallion Qualification Dollars (MQDs) for your trip.

Here’s how to do it, along with important details:

How to Add Your SkyMiles Number

1. Online (Best & Easiest Method):

   • Go to “My Trips” on Delta.com or in the Fly Delta app.
   • Retrieve your trip using your confirmation number and last name.
   • Look for an option to “Add SkyMiles Number” or “Edit Passenger Information.” You can usually add or update your frequent flyer number there.

2. Through the Fly Delta App:

   • Find your trip in the app.
   • Tap on your name or passenger details within the trip to edit and add your SkyMiles number.

3. By Phone:

   • Call Delta Reservations and provide your booking confirmation number. The agent can add your SkyMiles number to the reservation.

4. At the Airport:

   • You can add it at the check-in kiosk, with an agent at the ticket counter, or at the gate before your flight.

Key Points & Important Considerations

• Deadline: To ensure you earn miles, you should add your number before you check in for your flight. While you can sometimes add it after check-in or even after travel, it’s much less reliable. The safest rule is to add it at least 3 hours before departure.