Financial institutions make a killing off of fees. Whether it’s overdraft charges from the local bank or load fees charged by mutual funds, what you pay in fees can drain your finances and eat into your disposable income. Here are three avoidable fees that you might be paying:

Overdraft Fees

Overdraft fees are the granddaddy of them all. Earlier this year, CNN Money reported that banks are expected to collect $38.5 billion in overdraft fees. You can avoid overdraft fees by keeping track of your spending, especially when you use a debit card. This way, you are aware of how much you have, and you can keep a cushion in your checking account.

It can also help to link other accounts to your checking account. Some banks will let you link savings accounts, credit card accounts and additionally checking accounts to initiate automatic transfers that prevent overdraft. It's important to realize that “overdraft protection” usually comes with an annual fee and a relatively high interest rate.

Interest Charges

Credit card interest rates are notoriously high. You might be paying more than you imagine when you carry a balance. In order to avoid paying interest charges, you should be careful not to charge very much on your credit cards, and to pay them off every month.

You can get cheaper interest rates on auto loans and mortgages if you use credit responsibly and do your best to keep a good credit score.

Mutual Fund Fees

Mutual funds are famous for charging load fees, administrative fees and transaction fees related to turnover. Look for no-load mutual funds, and watch for funds that add loads to the back end. Additionally, you can save money in administrative fees by choosing index funds with low turnover.

— For more ways to save, spend, invest and borrow, visit MainStreet.com.