A survey overseen by a financial management website found that the fewest number of banks since 2009 offer fee-free checking accounts.

MoneyRates.com, a website launched by accountant and consumer financial adviser Richard Barrington, surveyed 100 banks, 50 larger asset ones and 50 smaller asset ones about their checking account fees. MoneyRates conducts the survey twice a year.

MoneyRates.com found that only 30% of banks offered checking accounts that are free of monthly maintenance fees and that the average monthly service fee was $12.43, while the average overdraft fee is now $31.60.

“Based on those average figures, a checking account customer who overdrafts his account three times in the course of a year would pay a total of $243.96 in monthly and overdraft fees for the year,” the site reported.

The survey also reported that online banks were more likely to offer fee-free checking accounts than banks with brick and mortar branches and attributed this difference to lower overhead on the parts of online banks.

“When people bank online, banks save money on everything from the cost of sending out statements to the expense of staffing their branches,” Barrington says. “The amount of free online checking accounts reflects that savings, and also represents an incentive for people to bank in more cost-effective ways.”

The survey did not report any data from credit unions.