Some people might refer them as a “nickel and dime” annoyances, but big businesses earn big profits from fees. In most cases, the fees are small enough that people don’t notice — or they decide it’s not worth doing anything about.

In recent months, two news reports have provided reminders of some of the worst offenders — big banks and airlines.

Last week, Citizens Bank was ordered to pay $34.5 million in refunds to customers and penalties for what could be considered a “nickel and dime” practice. Federal regulators found that whenever Citizens found a discrepancy between a customer’s deposit transaction and the actual amount being deposited, it kept the difference. The New York Times, commenting on the practice saying that what might be “a rounding error to a bank is real money to a customer.”

Citizens, which operates in 11 states including Pennsylvania, said it only resolved larger discrepancies, greater than $50 at the time reviewed by federal authorities. Regulators found that smaller discrepancies in the bank’s favor were not corrected.

The bank was ordered to repay $14 million in refunds and $20.5 million in penalties to resolve the action that affected 475,000 account holders from 2008 to 2013.

Just a few years ago, public frustration over banks’ manipulation of overdraft fees led to congressional action. The public learned that banks often processed debit card transactions out of order, moving the largest charge and triggering the overdraft fee first. Then, each subsequent and often smaller transaction would let the bank hit the customer with another $35 fee.

Banks make lots of money by charging fees. But recent actions by regulators and greater awareness by consumers have brought fee income down. Still, it’s a major source of profits, amounting to $32.5 billion for the banking industry in 2013, down from $41.1 billion in 2009.

Beyond banking, the airline industry boosts profits by hitting flyers with extra fees. But the practice has caught the attention of federal regulators. Earlier this summer, a report from the U.S. Senate Commerce Committee called for a crackdown on airline fees and hidden costs that trip up many air travelers.

The report pointed to fees ranging from $100 to $400 for changing a ticket and baggage fees that go from $25 for the first bag to $40 for the second bag. The report suggested that airlines be forced to provide the actual costs involved in changing a ticket or bringing an extra piece of luggage on board.

When booking online, many air travelers click on seat maps that show seats available, but for an extra charge. These premium seats, priced from $25 to $80 per flight, are optional, but some airlines’ websites make it appear they are part of the normal process.

The result is that airline passengers often pay hundreds of dollars more than the stated price of the ticket. And this is coming at a time when airlines are making record profits, thanks in part to lower fuel costs.

The Times editorial concluded that “no corner of banking should go unpoliced.”

Greater awareness of these “nickel and dime” practices used by big business will help consumers protect themselves and possibly lead to new laws or regulations that force big business to be more transparent.