Often it’s the smallest charge that triggers the biggest fee.
Overdraft fees, which is what banks charge when transactions including debit card purchases cause your account to drop below zero, average $35 — nearly twice the size of the average $20 debit card transaction, according to the Center for Responsible Lending.
Altogether, customers of larger banks paid more than $11 billion for bounced checks and other overdrafts in 2017, according to the most recent data from the Center for Responsible Lending. That does not include the fees collected by small community banks or credit unions, which are not required to report their fee volume to the FDIC.