I Thought I would answer this question today! This question comes to me almost on a regular basis:

Can you use Delta miles towards the cash price of a ticket and still get credit for the miles for the flight?

If you use both airline miles and cash to pay for your flight, you won’t get credit for the miles you fly. To earn miles on any airline or flight you have to actually pay for the ticket itself.

Now there are rewards programs that you can use to pay for airline tickets with rewards points and still earn the miles, but usually if you are paying for a flight with rewards points you aren’t getting the better value than if you were to pay for the same ticket with miles.

For instance, the American Express Membership rewards program allows me to use my rewards points to pay for airline tickets. If I were to fly from Seattle to Tampa and the cost of the ticket was $450, then the amount of rewards points I would need to pay for that ticket would be 45,000. But that same ticket I could get for a low as 25,000 Delta SkyMiles (obviously it would matter on when I flew but I have seen tickets from Seattle to Tampa for 25k).

The main benefit with paying for an airline ticket with rewards points is that I would earn the miles from the flights. The bad thing about spending points for flights like this is the value of your rewards drops, you get much less than you would have gotten if you just used a miles card such as the Delta/AMEX card.

To really get a better value, I push all my spending into my American Express membership rewards program, then wait for a transfer bonus to one of their partner airlines such as British Airways or even Delta. BA has had 2 or 3 – 50% transfer bonuses in the past year, so 50,000 rewards points turns into 75,000 airline miles. Now getting back to the question.. I would never pay half cash and half miles.

I just did a quick test for a ticket from Anchorage (where I live) to Tampa at the end of this month (July). Cost is $905, I could pay 25,000 miles and drop my ticket price by $250. 25,000 miles to me can get me a ticket price at least $550+ (it cost more to travel from Alaska).

So its best to either pay for the entire ticket with a credit card or pay for the entire ticket with all miles.

If you fly with Delta and choose to pay part of the ticket with miles, you will see a green bar on the left side of the checkout page that says this: “You’ve selected a Pay with Miles eligible itinerary. If you choose to Pay with Miles, this itinerary will not be eligible for mileage accrual and may not be eligible for upgrades.”

You can also read their Terms of Service on paying with miles: Pay with Miles tickets are not eligible for mileage accrual, Medallion Qualification Segments, Medallion Qualification Miles, or Best Fare Guarantee. Medallion Complimentary Upgrades on Pay with Miles tickets is limited to Diamond, Platinum, and Gold Medallion passengers and may not be eligible on all flights.