How interest on savings actually works

Banks pay you interest because they lend out the money you deposit. When you put $1,000 in a savings account, the bank uses that money to make loans to other customers—mortgages, car loans, business loans. The borrowers pay the bank interest on those loans. The bank keeps some of that interest as profit and pays you a portion of it as a reward for letting them use your money.

The amount the bank pays you is called the interest rate, shown as a percentage. A 4.5% annual percentage yield (APY) means the bank will pay you 4.5% of your account balance over one year, assuming the rate stays the same and you don't withdraw anything. On $1,000, that's $45 per year. The actual dollars appear in your account as a deposit, usually monthly or daily depending on the bank.

Interest rates change constantly because they follow what the Federal Reserve does with its own rates. When the Fed raises rates, banks raise the rates they pay on savings. When the Fed lowers rates, banks lower what they pay you. This is why the rate you see today may not be the rate you get next month.

Key Takeaways

  • Banks pay interest because they lend out your deposits to other customers and share a portion of the interest they collect.
  • The interest rate is shown as an APY (annual percentage yield) and tells you what percentage of your balance you'll earn over one year.
  • Higher interest rates appear on accounts with restrictions—money market accounts require larger deposits, high-yield savings accounts may limit withdrawals, and certificates of deposit lock your money away for a set time.
  • Interest compounds, meaning you earn interest on your interest, so the longer money sits untouched the more it grows.
  • The bank can change your interest rate at any time, so rates you see advertised today may be different next month.

Where to find the highest interest rates

The highest rates right now are on high-yield savings accounts (HYSAs) and certificates of deposit (CDs). High-yield savings accounts at online banks currently pay rates that are roughly double what traditional brick-and-mortar banks pay. A large national bank might pay 0.01% APY on a regular savings account, while an online bank might pay 4.5% or higher on a high-yield account. The difference exists because online banks have lower overhead costs—no physical branches, fewer employees—so they pass savings to customers through higher rates.

Certificates of deposit (CDs) lock your money away for a fixed period—three months, six months, one year, five years—and in return pay a higher rate than a savings account. A one-year CD might pay 5.0% while a high-yield savings account pays 4.5%. The tradeoff is that you cannot touch the money without penalty. If you withdraw early, the bank charges a fee that eats into your interest earnings.

Money market accounts sit between regular savings and high-yield savings. They typically require a larger opening deposit (often $2,500 or more) and may limit how many withdrawals you can make per month. In return, they pay higher interest than regular savings but usually less than HYSAs.

How interest compounds and grows your money

Compounding is the reason your money grows faster the longer it sits. When the bank pays you interest, that interest gets added to your balance. The next time interest is calculated, you earn interest on the original amount plus the interest you already earned. This creates a snowball effect.

Here's a concrete example: You deposit $10,000 in a high-yield savings account paying 4.5% APY. After one year, you have $10,450. If the rate stays the same and you don't withdraw anything, after two years you have $10,920.25—not $10,900. That extra $20.25 is interest earned on the $450 interest from year one. After five years at the same rate, you have $12,462.82. The longer the money stays, the more compounding works in your favor.

Banks compound interest on different schedules. Some compound daily, some monthly, some quarterly. Daily compounding is best because interest gets added to your balance more often, giving you more chances to earn interest on your interest. The difference between daily and monthly compounding is small on modest balances but grows larger as your savings increase.

What happens when interest rates drop

Banks can lower your interest rate at any time without asking permission. They must notify you before the change takes effect, usually by email or mail, but they don't need your consent. If you have a high-yield savings account earning 4.5% and the Fed cuts rates, your bank may drop your rate to 3.8% or lower within weeks.

Certificates of deposit protect you from this because the rate is locked in for the entire term. If you buy a one-year CD at 5.0%, you get 5.0% for the full year even if rates fall to 2.0%. This is one reason CDs appeal to savers who want certainty, though it also means you miss out if rates rise.

When rates drop across the industry, your options are limited. You can move your money to a bank still paying a higher rate, but you'll need to open a new account and transfer funds. You can buy a CD to lock in a rate before it drops further. Or you can accept the lower rate and keep your money where it is for convenience.

Taxes on interest income

The interest you earn is taxable income. If you earn $500 in interest during the year, you owe federal income tax on that $500 (and state income tax in most states). The bank will send you a 1099-INT form in January showing how much interest you earned, and you report that on your tax return.

The tax you owe depends on your overall income and tax bracket. Someone in the 22% tax bracket who earns $500 in interest owes roughly $110 in federal tax on that interest. Someone in the 12% bracket owes roughly $60. This is why high-yield savings accounts matter more for larger balances—the higher interest rate has to overcome the tax hit.

If you earn less than $10 in interest during the year, the bank may not send you a 1099-INT form, but you still owe tax on it if you file a return. Keep your own records of interest earned so you can report it accurately.

Why some accounts pay more than others

The main reason online banks pay higher rates is cost. A brick-and-mortar bank pays for building leases, tellers, security, and branch management. An online bank has none of that. They pass the savings to customers through higher rates. Both are equally safe because both are insured by the FDIC (Federal Deposit Insurance Corporation) up to $250,000 per account type per bank.

Account type also matters. A regular savings account is designed for frequent access—you can withdraw anytime without penalty. A high-yield savings account is designed for money you plan to leave alone. A CD is designed for money you don't need for a specific period. Banks pay more for accounts where you're less likely to withdraw, because they can lend out that money with more confidence.

Competition drives rates up and down. When many banks are competing for deposits, they raise rates to attract customers. When deposits are plentiful and the Fed is cutting rates, banks lower what they pay. Checking the current rates at a few banks before opening an account takes 10 minutes and can mean hundreds of dollars in difference over a year.

How to move money to a higher-paying account

If your current bank is paying 0.01% and you find a high-yield account paying 4.5%, moving your money is straightforward. Open an account at the new bank—this takes 10 to 15 minutes online and requires an ID and Social Security number. Then transfer money from your old bank to the new one using an ACH transfer (automated clearing house). This is a free electronic transfer that takes one to three business days.

You don't have to close your old account immediately. Many people keep a small balance in their original bank for convenience while moving most savings to the higher-paying account. Once you're sure the new account works as expected, you can close the old one. Closing an account is free and takes one phone call or a few clicks online.

The only reason not to move is if you're in a CD with a penalty for early withdrawal. If you have $5,000 in a CD paying 3.0% with six months left, and you withdraw early, the bank might charge a penalty of three months' interest ($37.50). In that case, it's usually better to wait out the CD term and then move the money.

Frequently Asked Questions

Can I lose money if interest rates drop?

No. Interest rates dropping means you earn less going forward, not that you lose what you already earned. If you have $10,000 earning 4.5% and the rate drops to 2.0%, you still have $10,000—you just earn less interest each month. The only exception is if you own a bond or bond fund, which is different from a savings account.

Is a high-yield savings account safe?

Yes, as long as the bank is FDIC-insured. FDIC insurance protects up to $250,000 per account type per bank. Most online banks are FDIC-insured. Before opening an account, check the bank's website or call and ask if they're FDIC-insured. If they are, your money is protected even if the bank fails.

What's the difference between APY and APR?

APY (annual percentage yield) includes compounding, so it shows the real amount you'll earn. APR (annual percentage rate) does not include compounding. For savings accounts, always look at the APY because that's what you actually get. APR is used for loans and credit cards.

Do I have to report interest under $10?

The bank doesn't have to send you a 1099-INT form if you earn less than $10, but you still owe tax on it if you file a return. Keep your own records of all interest earned and report it on your tax return to be safe.

Can a bank change my interest rate without warning?

A bank can change your rate, but they must notify you first. They'll send an email or letter before the change takes effect. You can't stop them from lowering the rate, but you can move your money to another bank if you don't like the new rate.