I don't pay any bank fees, except rental on my safe deposit box. That leaves me of two minds about the fees. On the one hand, I feel bad because the fees tend to fall hardest on the people who can afford them the least — the poor, the ignorant, the stupid, the careless, the lazy, and the unlucky. On the other hand, the fees other people pay help cover the costs of the many free services that I get from the bank. (See also: 7 Banks Still Offering Free Checking and Great Interest Rates)

Economic research firm Moebs Services just announced results from a survey that indicated that fees are now providing the bulk of bank profits. In fact, at almost half of all banks, overdraft fees alone exceed total bank profits.

Banks use a lot of tricks to maximize the fee income. In particular, they process the largest checks first. If one big check overdraws your account, the bank can then charge an overdraft fee on every check that clears. If they processed the checks in the opposite order, they might only be able to charge the overdraft fee on the last one. (Another trick is to add new fees with little fanfare, so that you don't know you're paying them until you check your bank statement.)

Most people are like me, paying little or nothing in the way of bank fees. For example, according to an FDIC report last year, less than 14% of all bank customers pay over 93% of the overdraft fees.

Although the poor tend to get hit most with fees, it isn't primarily the poverty that does it. The key to avoiding bank fees is keeping your finances under control. The only way that just being poor exposes you to fees is that the narrower the gap between your income and your expenses, the harder it is to keep your finances under control. You have less room for error and are more vulnerable to simple bad luck. But being poor tends to be associated with other things that make it tougher to avoid bank fees.

If you're poor, you can't afford to keep a large minimum balance. If your parents were poor, they may never have learned that it's not necessary to pay ATM fees and bank transfer fees and fees to check your balance and fees to talk to a teller. And whole categories of poor people are not only poor — they're poor and they don't speak English, or they're poor and they come from a cultural background that doesn't trust banks. These people easily fall victim to predatory firms that charge huge fees for services like check cashing and small loans.

So, poor or not, how do you avoid bank fees? After the obvious things — don't overdraw your account and don't go over the limit on your credit card — the most important step for avoiding bank fees is to read the stuff from your bank and understand what services are free and what services aren't. Every bank makes many services available free to certain customers — you just need to make sure that you're one of those customers.

Common Special Deals

Bank fee structures are, of course, ridiculously complicated. Most banks have multiple fee structures, depending on things like what kinds of accounts you have, which services you use, minimum balance, and even age (seniors often get good specials; students often get crappy ones). There are a few practices that show up pretty often, even if they're not universal, so it's worth being aware of them.

High minimum balance

Lots of banks offer no-fee deals for people who keep a certain minimum balance. (At some banks there are several tiers of these.) With interest rates as low as they are now, it costs very little to leave some cash lying around in your checking account. It'd take a couple years for the lost interest from having $1000 sitting idle in your checking account instead of in an internet savings account to add up to as much as just one bounced check fee.

Packages of accounts

Lots of banks offer package deals, where certain fees are waived if you get a certain group of accounts (savings, checking, line of credit, etc.). The idea is that if they can pull in a certain critical mass of your financial activity, it'll increase the chance that you'll use them for other, high-profit services like your mortgage and your IRA.

Packages of services

Many banks have long waived some fees if you have your paycheck directly deposited into the bank. More recently, some banks have started offering higher rates to people who agree to some minimum number of debit card transactions. Others offer deals to people who use the bank's bill paying service.

Any of these can be a excellent deal if the packages or minimums happen to match how you were going to arrange your finances anyway. The banks are all a little different, so look around and see if you can find one that's a good match.

This is another place where the poor tend to get nailed: If they live in a poor neighborhood, they probably don't have a dozen different local banks to choose from, reducing the chance that they can find one that offers a deal that matches their circumstances.

Other Financial Fees

Because there's so much money in fees for financial services, everybody is trying to get in on it — including states. Many states have started making cash assistance (unemployment, food stamps, etc.) available via a debit card — but a debit card that comes loaded up with fees: fees for using an ATM, fees for checking your balance, fees for trying to charge more than is left on your card. There are even fees for not using your card! (That probably doesn't deserve an exclamation point — lots of kinds of accounts have inactivity fees these days — but I still find it shocking.)

Like with other bank fees, most of these are avoidable if you understand the rules, and not too onerous as long as the cash assistance isn't your only source of income.

The easiest thing to do for things like unemployment insurance where you're allowed to get the money as cash, is to do just that. You typically get one free cash withdrawal per month at an in-network ATM. Use it to get all the money out and put it into your regular bank account. If you're not allowed to get the money as cash (as with debit cards for food stamp benefits), you can minimize fees by treating it like an ordinary debit card — track each transaction and keep a running balance so you don't have to pay a fee to check the balance. Then, use the card to pay for whatever's allowed until the money runs out.

Avoiding fees is pretty straightforward for people whose finances are under control. They know what services they need, so they can shop around and find out which banks offer those as free services (with which kinds of accounts). They pay attention to things like which ATMs they can use for free. They keep track of their balance and don't overdraw their account. If they need a service that isn't free, they shop around to find where they can get it cheapest.

It's not that much work to nail down all these details, and over time it can save a fortune in fees.