i am starting to believe citibank waive annual fee based on number of swipes in a year, not how much you spend. Reason is probably number of swipes is taken into consideration for citi merchant subscription. Also, the fact that citi doesn't waive for all who spend 20k, does not waive for all who has installment and does not waive for all who has been a customer for more than 10 years. Should be the number of swipes.