Banks take deposits, lend money out, and keep the difference as profit

A bank is a business that holds money for you and lends that money to other people and businesses. When you deposit money into a checking or savings account, the bank doesn't lock it in a vault with your name on it. Instead, the bank uses your money—along with deposits from thousands of other customers—to make loans. The bank pays you a small amount of interest on your deposit (or nothing, depending on the account). The bank then charges borrowers a higher interest rate on those loans. That gap between what the bank pays depositors and what it charges borrowers is how the bank makes its profit.

This system works because not every customer withdraws their money at the same time. A bank can safely lend out most of the money it holds because statistically, enough deposits will stay in the bank to cover daily withdrawals. Banks are required by law to keep a minimum amount of cash on hand—called a reserve requirement—so they can always meet withdrawal requests. The Federal Reserve sets these rules and oversees how much banks must hold.

Key Takeaways

  • Banks profit by borrowing your money at a low interest rate and lending it to others at a higher rate.
  • Your deposits are insured by the Federal Deposit Insurance Corporation (FDIC) up to $250,000 per account type, so your money is protected even if the bank fails.
  • Banks charge fees for services like overdrafts, wire transfers, and account maintenance, which is another source of income.
  • Banks are required to keep a portion of deposits in reserve and cannot lend out every dollar customers deposit.

How banks lend your money

When you deposit $5,000 into a savings account, that money doesn't sit idle. The bank immediately begins using it. If a small business owner walks in and needs a $50,000 loan to buy equipment, the bank might lend money from its pool of deposits—including yours—to that business. The business owner pays back the loan with interest over time, and the bank keeps a portion of that interest as profit.

The same process happens with mortgages, car loans, and credit cards. A mortgage lender uses depositor money to fund home loans. A credit card company uses deposits to cover the balance when you swipe your card. Each of these loans generates interest income for the bank. The bank also sells some loans to other financial institutions, which is another way banks move money around and generate fees.

Banks manage risk by not lending out 100 percent of deposits. They also spread loans across many borrowers so that if one borrower defaults, the bank doesn't collapse. Banks also charge higher interest rates to borrowers with worse credit histories, which compensates them for the higher risk of default.

Where your deposit protection comes from

The Federal Deposit Insurance Corporation (FDIC) insures deposits at member banks. If a bank fails, the FDIC pays depositors up to $250,000 per account type at that bank. This protection exists because of the Great Depression, when bank failures wiped out millions of people's savings. The FDIC was created in 1933 to prevent that from happening again.

Your money is insured separately for each account type you hold at the same bank. A checking account, a savings account, and a money market account are each insured up to $250,000. If you have $200,000 in checking and $200,000 in savings at the same bank, both are fully protected. If you have $300,000 in one checking account, only $250,000 is covered by FDIC insurance.

FDIC insurance does not cover investment accounts, brokerage accounts, or money you invest in stocks and bonds through a bank. It only covers deposits in bank accounts. If you want to protect more than $250,000 at one bank, you can open accounts in different names (such as a joint account with your spouse) or spread money across multiple banks.

The fees banks charge

Interest income is not the only way banks make money. Banks also charge fees for services and for mistakes. An overdraft fee is charged when you spend more money than you have in your account. A wire transfer fee covers the cost of sending money electronically to another bank. Monthly maintenance fees are charged on some accounts, though many banks waive these fees if you maintain a minimum balance.

Banks also charge fees for services like cashier's checks, stop payments on checks, and replacing a lost debit card. Some banks charge fees for using an out-of-network ATM. These fees add up across millions of customers and represent a significant portion of bank revenue. In recent years, some banks have reduced or eliminated overdraft fees in response to customer complaints and regulatory pressure, but the practice remains common.

How banks manage risk

Banks cannot lend out every dollar they receive in deposits. The Federal Reserve requires banks to hold a minimum percentage of deposits in reserve—money that cannot be lent out. This reserve requirement varies depending on the size of the bank and the type of deposit, but it ensures banks can always cover customer withdrawals.

Banks also manage risk by diversifying their loans. A bank that lends only to real estate developers is more vulnerable to a housing market crash than a bank that lends to developers, small businesses, manufacturers, and consumers. Banks also use credit scores and financial statements to assess whether a borrower is likely to repay a loan. Borrowers with higher credit scores get lower interest rates because they pose less risk of default.

Banks also hold capital—money the bank owns rather than money deposited by customers. This capital acts as a cushion. If loans go bad and borrowers default, the bank uses its own capital to cover losses before depositor money is at risk. Regulators require banks to hold a certain amount of capital relative to the loans they make, which limits how much a bank can lend.

What happens when you borrow from a bank

When you take out a loan, you are borrowing money that the bank has collected from depositors. The bank charges you interest, which is the cost of borrowing. The interest rate depends on the type of loan, the length of the loan, your credit score, and current market conditions. A mortgage might have an interest rate of 6 percent, while a credit card might charge 18 percent or higher.

The bank makes money on the difference between what it pays depositors (often close to zero on checking accounts) and what it charges you (6 percent on a mortgage). If the bank pays 0.5 percent interest on savings accounts and charges 6 percent on mortgages, the bank keeps 5.5 percent as profit. Multiply that by millions of loans and billions of dollars, and the profit becomes substantial.

How banks invest depositor money

Banks do not lend out every dollar in deposits. Some deposits are invested in government bonds, corporate bonds, and other securities. These investments generate income for the bank and also provide safety—government bonds are considered very low-risk investments. Banks balance lending and investing to manage risk and generate returns.

During economic downturns, banks may hold more money in bonds and less in loans because lending becomes riskier. During economic booms, banks may lend more aggressively because borrowers are more likely to repay. Banks also trade securities and currencies, which generates additional income but also exposes the bank to market risk.

Frequently Asked Questions

What happens to my money if the bank fails?

The FDIC insures deposits up to $250,000 per account type. If your bank fails, the FDIC pays you directly, usually within a few business days. You do not lose money as long as your balance is within the insurance limit. Deposits above $250,000 are not protected by FDIC insurance.

Do banks pay interest on checking accounts?

Most checking accounts pay little to no interest. Some banks offer checking accounts with higher interest rates, but they usually require a large minimum balance or frequent deposits. Savings accounts and money market accounts typically pay higher interest rates than checking accounts, though rates vary widely by bank and change frequently.

Can a bank use my money without my permission?

Yes, banks use depositor money to make loans as part of normal banking operations. This is how banks function and how they generate the interest income that allows them to pay you interest on your deposit. Your money is not sitting in a vault; it is being lent to other customers. This is legal and standard practice at all banks.

Why do banks charge overdraft fees?

Banks charge overdraft fees when you spend more than your account balance because processing an overdraft costs the bank money and exposes it to risk. The fee is meant to discourage overdrafts and compensate the bank for the cost. However, overdraft fees are controversial because they disproportionately affect low-income customers who live paycheck to paycheck.

How do banks decide who gets a loan?

Banks use credit scores, income, employment history, and existing debt to decide whether to lend money and at what interest rate. A higher credit score usually means a lower interest rate. Banks also consider the purpose of the loan—mortgages are considered lower-risk than personal loans, so mortgage rates are typically lower.