American Express recently stopped counting airline gift card purchases towards airline incidental credit reimbursements.  

As a reminder, the airline credits are intended to be used for incidental fees such as checked bags and in-flight refreshments, and not gift cards.

Since the gift cards stopped coding, there have been scattered data points of select non-gift card transactions triggering the airline incidental fee reimbursement.

Some of the data points below are of legitimate airline incidentals like seat upgrades, pet fees, and early check-in fees. If you believe that your purchase should be considered an incidental and it’s not reimbursed by your statement close, contact American Express and let them know.

Disclaimer: Data points do not mean that the method is guaranteed to work. Methods are subject to change at any time. Use at your own risk.  
 

Alaska Airlines

• One-way low cost fares under $100 can qualify. Data point 1

American Airlines

• See a roundup of fees being reimbursed here: https://www.flyertalk.com/forum/31268064-post1930.html
• Generally a skip but lots of normal incidentals.

Delta

• Award ticket fees under $100: Data point 1
• Additional collection: Data point 1, 2, 3, 4

Credits are getting reimbursed ~10 days from transaction posting (NOT transaction date).

i.e., you make the purchase on Nov 15 and it posts on Nov 18. It would be ~10 days from 18th so hopefully 28th.

Works:

• up to $250 additional collection via the Amex Platinum (charge, reimbursement)

Doesn’t work:

• Gift cards do NOT get reimbursed (as of June 22, 2019)
• Delta Sky Club bar no longer works (as of Sep 2023)

Frontier

• Low fares under $100: Data point 1

Hawaiian

• Seat upgrades: Data point 1, 2
• Partial airfare charges ( under $50 ): Data point 1

JetBlue

• One-way airfare under $100: Data point 1
• Pet fees: Data point 1
• Seat upgrade: Data point 1

Works:

• Extra legroom purchases (needs to be separate transactions)
• Cancellation fees
• Tickets exactly between $137.40 and $152.20 (i.e., $142) (see)

Doesn’t work:

• Gift cards

Southwest

• Early bird check-in fees: Data point 1
• Award ticket fees: Data point 1
• One-way airfare under $100: Data point 1, 2, 3

Works:

• Flight tickets less than $109
• Additional collections below $109 (i.e., $208 ticket + apply a $100 credit = $108 remainder)

Doesn’t work:

• Gift cards

United

• Award fees under $100: Data point 1
• Partial airfare charges under $100: Data point 1
• Works: TB