snic

I bought some meals on a flight on 12/31. The purchase took me over the fee credit amount for 2016, but I noticed that Amex reimbursed the entire amount. Even though the "pending" transaction was dated 12/31, it posted with a 1/1 date, and I suspected that Amex applied the 12/31 purchases to the 2017 credit.

So I contacted Amex via online chat and the agent said she fixed it so that the charges would apply towards the 2016 credit (and I'd be charged the extra amount that had been reimbursed but shouldn't have been).

(Note that this could actually work to your advantage: if you have a 12/31 flight and have maxed out the credit for the year, the in-flight charges will most likely apply to next year and will get automatically reimbursed.)