Update 3/3/24: Reader Mark R notes that AmEx now shows clearly on the earning statement which card is getting the referrer bonus. See also this comment.
Original Post 1/9/24:
We received a neat tip from usccstrategy which simplifies figuring out which card you used when referring a friend to an Amex card:
- Look at your rewards transactions showing the referrer bonus. You’ll see there a string of letters/numbers attached to each referral bonus. Example:
- See in the above screenshot one of the referrals is described as “K3QE” and one is described as “K3YC”.
- Next, check your referral link. Look at the full expanded version of the link. Near the end of the long link you’ll see the 4-digit code which represents the card for referrals. That code will correspond to the code you see in the login.
For example, one code I checked ends with “92-201279-K50U%3A9997&v=1&xl=cp10gx”. If that card would refer a friend, they would see “K50U” in their rewards login. Cool.