Banks earn money mainly by lending out the deposits you keep with them, and by charging fees for services

When you put money in a bank account, the bank does not lock it in a vault with your name on it. Instead, the bank uses your deposit to lend money to other customers — for mortgages, car loans, credit cards, and business loans. The bank charges those borrowers interest, which is a percentage of the loan amount. The difference between the interest the bank collects from borrowers and the interest it pays you on your savings is the bank's main profit.

Banks also make money from fees — charges for services like overdraft protection, wire transfers, monthly account maintenance, or using another bank's ATM. Some accounts charge a monthly fee unless you keep a minimum balance. Others charge you when you go over your balance by accident. These fees add up across millions of customers and represent a significant portion of bank revenue.

Key Takeaways

  • Banks lend out customer deposits to borrowers and keep the difference between what they pay depositors in interest and what they charge borrowers.
  • The interest rate you earn on savings is typically much lower than the rate borrowers pay on loans, which is where banks profit.
  • Monthly fees, overdraft charges, and transaction fees are a second major source of bank income.
  • Banks also invest customer deposits in stocks, bonds, and other securities, and keep the returns from those investments.
  • The more money a bank holds in deposits, the more it can lend out and the more interest income it generates.

How the interest spread works

The interest spread is the gap between what a bank pays you and what it charges borrowers. Say your savings account earns 0.01% annual interest. That means on $10,000, you earn about $1 per year. Meanwhile, a customer taking out a mortgage might pay 6% or 7% interest. On a $300,000 loan, that is $18,000 to $21,000 per year in interest payments to the bank.

The bank keeps most of that difference. It pays you $1, collects $18,000 to $21,000, and uses the rest to cover its own costs — employee salaries, building rent, technology systems, insurance — and to build profit. This spread is the reason banks can afford to offer you a checking account with no monthly fee: the interest income from lending far exceeds what they spend on your account.

The size of the spread changes based on what the Federal Reserve does with interest rates. When the Fed raises rates, banks can charge borrowers more, but they also have to pay depositors more to keep their money. When the Fed lowers rates, both sides shrink. Banks prefer a wide spread, so they lobby for policies that let them pay depositors as little as possible while charging borrowers as much as the market will bear.

Fees and charges

Banks charge fees for specific services and for account behavior. A monthly maintenance fee is a flat charge just for having the account open — though many banks waive this if you keep a minimum balance or set up direct deposit. An overdraft fee is charged when you spend more money than you have in your account; the bank covers the difference and charges you a penalty, often $25 to $35 per overdraft.

Other common fees include charges for wire transfers (sending money to another bank), ATM fees (if you use a machine that is not owned by your bank), foreign transaction fees (if you use your card abroad), and fees for stopping a check or requesting a copy of an old statement. Some accounts charge a fee if your balance drops below a certain amount, or if you make too many transfers in a month.

These fees seem small individually — $2 here, $5 there — but across a bank's customer base they generate billions of dollars annually. A bank with 10 million customers charging an average of $15 per month in fees brings in $1.8 billion per year from fees alone, before counting any interest income.

Investment income and other sources

Banks do not just lend out deposits; they also invest them. A bank might use some of its customer deposits to buy government bonds, corporate bonds, or stocks. When those investments pay dividends or interest, the bank keeps the returns. This is another source of profit separate from lending.

Banks also earn money from services beyond basic accounts. They charge for wealth management (advising rich customers on investments), for underwriting (helping companies issue stock or bonds), for trading securities on behalf of customers, and for custodial services (holding investments for you). Investment banks — which operate differently from consumer banks — earn large fees from mergers, acquisitions, and complex financial deals.

Some banks also own insurance companies or investment firms, and profits from those subsidiaries flow back to the parent bank. The largest banks are financial conglomerates with many revenue streams, though the core business remains deposits and lending.

Why banks need your deposits

A bank cannot lend money it does not have. The deposits customers place in savings and checking accounts are the raw material the bank uses to make loans. The more deposits a bank holds, the more it can lend, and the more interest income it generates. This is why banks advertise savings accounts and offer perks like higher interest rates or bonus cash — they are competing for your deposit dollars.

Banks are also required by law to keep a certain percentage of deposits on hand as a reserve, though the Federal Reserve can change this requirement. This reserve protects customers: if many people try to withdraw money at once, the bank has cash available. The reserve requirement also limits how much a bank can lend relative to its deposits, which is another reason banks want to attract large deposit balances.

How interest rates affect what banks pay you

The interest rate you earn on a savings account is not set by the bank alone. It is influenced by the federal funds rate, which is the interest rate the Federal Reserve sets for banks to lend to each other overnight. When the Fed raises this rate, banks' costs go up, and they eventually raise the rates they offer depositors to stay competitive. When the Fed lowers rates, banks lower what they pay you.

However, banks do not pass along rate changes equally. When the Fed raises rates, banks often raise what they pay depositors slowly and by small amounts, while raising what they charge borrowers quickly and by larger amounts. When the Fed lowers rates, banks cut what they pay depositors when ready and sharply, while lowering borrower rates more slowly. This behavior widens the spread in the bank's favor during rate cuts and narrows it during rate increases — another way banks protect their profits.

The relationship between deposits and bank stability

A bank's ability to stay in business depends on maintaining enough deposits to cover withdrawals and fund loans. If a bank loses deposits — because customers move their money elsewhere or because of a bank failure — it has less money to lend and less interest income. This is why banks insure deposits through the Federal Deposit Insurance Corporation (FDIC), which guarantees that if a bank fails, the government will return your money up to $250,000 per account.

The FDIC insurance itself is funded by fees banks pay, not by taxpayers. Banks pay a small percentage of their deposits into the FDIC insurance fund. This is another cost to the bank, but it is necessary because without deposit insurance, customers would be afraid to keep money in banks, and the entire banking system would collapse.

Frequently Asked Questions

Why do banks pay such low interest on savings accounts?

Banks pay low interest because they do not need to pay much to attract deposits. Most people keep money in banks for safety and access, not for investment returns. Banks pay just enough to keep customers from moving their money elsewhere, while keeping the interest spread as wide as possible. When competition increases or the Fed raises rates, banks raise savings rates — but they lag behind, which is why shopping around for a high-yield savings account can pay off.

Do banks make money if I never use my account?

Yes. Even if you never write a check or make a transfer, the bank is using your deposit balance to lend to other customers and earn interest. Your money is working for the bank whether you use the account or not. This is why banks are willing to offer free checking accounts — the deposits themselves are valuable.

What happens to my money if the bank fails?

The FDIC insures deposits up to $250,000 per depositor per bank. If a bank fails, the FDIC pays you back in full up to that limit, usually within a few business days. Money over $250,000 is at risk, which is why people with large balances spread deposits across multiple banks or use accounts specifically structured to maximize FDIC coverage.

Can I earn more interest by keeping a larger balance?

Not usually. Most savings accounts pay the same interest rate regardless of balance size — a $1,000 balance and a $100,000 balance earn the same percentage. However, some banks offer tiered rates where larger balances earn slightly higher rates, and money market accounts sometimes pay more interest if you maintain a high minimum balance. Always check your account terms.

Why do banks charge overdraft fees if they are already making money from my deposits?

Overdraft fees are profit on top of the interest spread. Banks argue that overdraft fees compensate them for the risk and cost of covering a shortfall, but the fees are often much larger than the actual cost. Overdraft fees are controversial because they disproportionately affect people with lower balances and less stable income — the customers least able to afford them.