Banks profit from deposits the moment you put money in, by lending it out at a higher interest rate than they pay you

When you deposit money into a savings account or checking account, the bank doesn't lock that money in a vault with your name on it. Instead, the bank lends most of it to other customers — for mortgages, car loans, credit cards, business lines of credit. The bank pays you a small interest rate on your deposit, then charges borrowers a much larger interest rate on their loans. That gap is the bank's primary source of profit from your account.

This happens immediately. The bank begins using your deposit to fund loans as soon as the transaction clears, which is typically one to two business days after you make the deposit. You don't have to wait for anything or sign anything extra — the moment you hand over the money, the bank's profit engine starts running.

Key Takeaways

  • Banks lend out the majority of customer deposits to other borrowers and keep the difference between what they pay depositors and what they charge borrowers.
  • A bank paying you 0.01% annual interest on savings while charging a borrower 6% on a personal loan keeps roughly 5.99% as profit on that transaction.
  • The Federal Reserve sets a baseline interest rate that influences how much banks pay depositors and how much they charge borrowers, so deposit rates rise and fall with Fed policy.
  • Banks must keep a small percentage of deposits on hand as a reserve requirement, but the rest is available to lend out immediately.
  • Your deposits are insured up to $250,000 per account type at FDIC-insured banks, regardless of how the bank uses the money.

The interest rate spread: what the bank keeps

The difference between the rate a bank pays you and the rate it charges borrowers is called the net interest margin. This is where banks make most of their money from deposits.

In 2024, a typical savings account at a major bank pays around 0.01% to 0.05% annual interest. Meanwhile, that same bank might charge 6% to 8% on a personal loan, 3% to 7% on a mortgage, or 15% to 25% on a credit card. On a $10,000 deposit, the bank might pay you $1 per year while charging a borrower $600 per year on a $10,000 personal loan funded partly by your deposit. The bank keeps the difference.

Online banks and credit unions often pay higher deposit rates — sometimes 4% to 5% on savings accounts — because they have lower overhead costs and less need to attract deposits through physical branches. But even at 5%, if a bank lends that money at 8%, the margin is still 3%, and that's profit.

How the Federal Reserve affects what banks pay you

The Federal Funds Rate, set by the Federal Reserve, is the interest rate at which banks lend money to each other overnight. It's not a rate you see directly, but it's the foundation for almost every other interest rate in the economy.

When the Fed raises its rate, banks have to pay more to borrow from each other, so they raise the rates they offer on deposits to attract money. When the Fed cuts rates, banks lower deposit rates because they can borrow more cheaply. Between 2020 and 2022, the Fed raised rates from near zero to over 5%, and deposit rates climbed from nearly nothing to 4% or 5% at competitive banks. In 2023 and 2024, as the Fed held rates steady and then began cutting, deposit rates started falling again.

This means the interest you earn on your savings is not something the bank chooses out of generosity — it's a response to what the Fed does and what competing banks offer. If you're earning 0.01% at a major bank while online banks offer 4%, you're seeing the result of that bank choosing not to compete for deposits.

Reserve requirements and how much banks can lend

Banks cannot lend out 100% of customer deposits. The Federal Reserve requires banks to hold a minimum percentage of deposits in reserve — money that must stay in the vault or in an account at the Fed itself, not lent out.

As of 2024, reserve requirements vary by the size of the bank and the type of account. For most banks, the requirement is around 10% of certain deposit categories, though the Fed has reduced or eliminated reserve requirements for many institutions in recent years. This means if you deposit $1,000, the bank might keep $100 in reserve and lend out $900.

The reserve requirement exists to ensure banks can handle withdrawals if many customers ask for their money at once. It's a safety mechanism, not a limit on profit — the bank still makes money on the 90% it lends out, and the 10% in reserve earns interest at the Fed (currently around 5.33% as of 2024), which the bank also keeps.

Other ways banks profit from deposits

Interest margin is the biggest source of deposit-related profit, but it's not the only one. Banks also charge fees on deposit accounts — monthly maintenance fees, overdraft fees, ATM fees, wire transfer fees. These fees don't depend on how the bank uses your money; they're charged directly to you for the service of holding the account.

Banks also invest deposits in securities like bonds and Treasury bills, which pay interest. A bank might take customer deposits and buy a 10-year Treasury bond paying 4%, pocketing the difference between that 4% and the 0.01% it pays depositors. This is less risky than lending to individuals because the U.S. government backs the bond, but it's still profit.

Some banks also sell customer data (anonymized and aggregated) to marketers and financial firms, or cross-sell products like credit cards and investment accounts to depositors. These revenue streams are smaller than interest margin, but they add up across millions of accounts.

Why banks pay you so little on deposits

If banks make so much money from deposits, why do they pay depositors almost nothing? The answer is competition and cost.

Major banks like Chase, Bank of America, and Wells Fargo have massive branch networks, advertising budgets, and customer service operations. These costs are high, and they're spread across millions of accounts. A bank might spend $50 per year to maintain your account through staff, technology, and physical space. If it pays you 0.01% on a $1,000 balance, it's paying you $0.10 per year while spending $50 to keep the account open. The bank is still profitable because it lends out your $1,000 at a much higher rate.

Online banks have lower costs because they don't operate physical branches, so they can afford to pay higher deposit rates and still be profitable. But even online banks don't pay rates as high as what they charge borrowers — the margin is smaller, but it still exists.

Banks also don't have to compete aggressively for deposits when interest rates are low. If the Fed rate is near zero and all banks are paying 0.01%, customers have nowhere else to go. But when the Fed raises rates and online banks start offering 4% or 5%, traditional banks face pressure to raise their rates or lose deposits. This is why deposit rates change so dramatically when Fed policy shifts.

FDIC insurance protects your deposit regardless of how the bank uses it

Your deposits are insured by the Federal Deposit Insurance Corporation (FDIC) up to $250,000 per account type at each bank. This insurance covers you if the bank fails — you get your money back, even if the bank lost it all lending to borrowers who defaulted.

The FDIC insurance exists because banks do take risks with deposits. A bank might lend your money to a borrower who stops paying, or invest it in securities that lose value. If enough loans go bad, the bank can fail. The FDIC steps in and pays depositors from its insurance fund, which is funded by fees banks pay to the FDIC.

This means you don't have to worry about where your money goes or how the bank uses it. Your $250,000 is protected whether the bank lends it out, invests it, or loses it. The bank's profit from your deposit doesn't change your protection.

Frequently Asked Questions

Do I earn interest every day or only at the end of the year?

Most banks calculate and credit interest daily or monthly, not annually. If your account earns 4% annual interest, the bank divides that by 365 days and credits you roughly 0.011% each day. This compounds over time, so you earn interest on your interest. Check your account statement or bank website to see how often interest is posted to your account.

What happens to my deposit if the bank goes out of business?

The FDIC takes over and pays you up to $250,000 per account type. If you have $100,000 in a savings account and $100,000 in a checking account at the same bank, both are covered separately. The process usually takes a few days to a few weeks. You don't lose money as long as you're under the $250,000 limit per account type.

Why do online banks pay more interest than big banks?

Online banks have lower operating costs because they don't run physical branches or employ as many staff. They can afford to pay higher deposit rates and still make a profit on the interest margin. Big banks choose to pay less because they rely on brand recognition and convenience rather than competitive rates to attract deposits.

Can I move my money to a bank that pays higher interest?

Yes. You can open an account at any bank or credit union and transfer your money. There's no penalty for moving deposits, and the FDIC insurance follows you to the new bank. If you're earning 0.01% at one bank and another offers 4%, switching costs nothing and could earn you hundreds of dollars per year on a large balance.

Do banks make money from checking accounts if they pay no interest?

Yes. Banks lend out the money in your checking account the same way they lend out savings deposits, even though they pay you zero interest. They also charge overdraft fees, monthly maintenance fees, and ATM fees on checking accounts. The combination of interest margin and fees makes checking accounts profitable for banks.