When you make an AAdvantage® Debit Card transaction, we look at all the pending / uncleared AAdvantage® Debit Card transactions on your account.
If the sum of these exceeds the overall limits on your account, then your transaction will be rejected with the Maximum Pending message.
To resolve this issue, you need to wait for a set of AAdvantage® Debit Card transactions to clear over upcoming days, to essentially free up the utilisation.
You can see the amount of pending transactions by tapping on the 'balance' at the top of the home screen on your app, or you can see the status of specific transactions if they appear in grey within the app. They will be marked as cleared over subsequent days.