How do credit cards work? The short answer
A credit card lets you borrow money from a bank to pay for something now and pay it back later.3 When you tap the card, your bank approves the purchase, pays the shop (through the shop's bank) a little later, and adds the price to your balance, the amount you owe. Once a month you get a bill called a statement. Pay the whole balance by the due date and, on most cards, you pay no interest on purchases.12 Pay less and the bank charges interest on what's left, at a yearly rate called the APR.2
This page explains how credit cards work; it isn't financial advice.
What is a credit card?
Think of a credit card as a loan you can use in small pieces. The bank that gives you the card (the issuer) sets a credit limit: the most you can borrow at one time.14 If your limit is $1,000 and you buy a $500 bike, you can still borrow $500 more. When you pay some back, that room opens up again. If a purchase would take you over the limit, the bank can simply decline it.4
The limit isn't money you have. It's money the bank is willing to lend you, and every dollar of it has to be paid back.
What happens when you tap your card?
Paying by card takes a couple of seconds, but behind the beep there are several players: you, the shop, the shop's bank, your card's bank, and a card network that carries messages and money between the banks.5
- Tap. The shop's card reader sends your card details and the price into the card network.5
- Ask. The network passes the request to your bank: is this card real, and is there room under the limit?
- Approve. Within seconds your bank sends back its approval, and the reader beeps.16
- Settle. Later (shops usually send their sales in once a day), your bank sends the money through the network to the shop's bank. It keeps a small slice first: the interchange fee.5
- Add it up. The shop's bank pays the shop what's left, minus its own small fees. The full price goes onto your balance.5
So on a $500 bike, the shop might get about $490 while you owe the full $500. Credit card interchange fees generally range from about 1 to 3 percent of the price.6
The monthly statement, due date and grace period
Every billing cycle (usually a month) you get a statement listing what you bought, what you paid, and what you owe. By law the card company has to send it at least 21 days before the payment is due.13
The time between the end of the billing cycle and the due date is called the grace period. If you pay the full balance by the due date, you usually pay no interest on your purchases. Card companies don't have to offer a grace period, but most do for purchases.1 If you don't pay in full, you're charged interest on what's left, and you can lose the grace period on new purchases too.1 Cash advances usually start charging interest right away.1
How does credit card interest (APR) work?
A card's interest rate is the price you pay for borrowing. On credit cards it's given as a yearly rate, the annual percentage rate (APR).2 Many card companies work out interest every day from your average daily balance, using a daily periodic rate. Interest that isn't paid is added to the balance, so next time you're charged interest on it too. That's compound interest, working against you.89
Card rates are high compared with most loans. In the second quarter of 2026, the average APR on credit card accounts that were charged interest was 22.15% (Federal Reserve G.19, released September 8, 2026).7 Rates change over time and vary from card to card.
Simplified example: one month's interest ≈ unpaid balance × 22% ÷ 12. Real cards calculate daily and may charge interest on new purchases once you carry a balance.
Why paying only the minimum takes so long
Each statement shows a minimum payment. Paying at least that much by the due date avoids late fees and a black mark on your record, but interest is still charged on everything you didn't pay, so credit gets more expensive.3 If you miss even the minimum, your rate can go up, you can be charged a late fee, and your credit history can suffer.311
Here's what happens to that $500 bike at 22% APR if you pay a fixed amount every month (our calculation, simplified):
Small payments feel easy, but they stretch the debt out for years. That's why U.S. card statements must show an estimate of how long paying only the minimum would take, what it would cost in total, and how much you'd need to pay each month to clear the balance in three years.15 The longer you take to pay back money you borrowed, the more interest you pay.13
How do credit card companies make money?
Card companies earn money in a few main ways: interest, fees and interchange.19
- Interest. People who don't pay their full balance pay interest. In 2022, U.S. card companies charged consumers more than $105 billion in interest.10
- Interchange fees. Every time a card is used, the shop pays fees. The biggest one, the interchange fee, is set by the card network and goes to the bank that issued the card.5 It's usually about 1–3% of the price.6 Part of it may come back to cardholders as rewards like cash back or points.18
- Fees. Some cards charge a yearly (annual) fee.17 There are also late fees when a minimum payment is missed.11 In 2022, card companies charged more than $25 billion in fees, including over $14 billion in late fees.1020
Put together: someone who always pays in full mostly costs the shop a fee. Someone who carries a balance pays interest on top. It's the same idea banks use everywhere: borrow cheaply, lend for more (see how banks make money).
Credit card vs debit card
Sources for this table: FDIC and FTC.43
What is a credit score, and what does a card have to do with it?
A credit score is a number that predicts how likely you are to pay back a loan on time, worked out from your credit report. It looks at things like your bill-paying history and how much of your available credit you're using. Most scores run from 300 to 850.12 Lenders, landlords and even insurers use it, and it can affect the interest rate and credit limit you're offered.12
Your ability to borrow later depends mostly on your record of paying back on time, and paying bills on time helps raise your score.13 Money works the same way elsewhere: prices tend to rise over time (see what causes inflation), and interest can work for you when you save or invest instead of borrow (see how the stock market works).
Common misconceptions
"Tapping a card spends my money." With a credit card, you're spending the bank's money, and you owe it back.
34
"Credit cards always charge interest." On most cards, paying the full balance by the due date means no interest on purchases.
2
"If I pay the minimum, I'm fine." You avoid a late fee, but interest keeps growing on the rest, and payoff can take years.
3
"My credit limit is money I have." It's only the most the bank will lend you at once.
14
"The shop gets the full price." The shop pays fees on every card sale, the biggest being interchange.
5
A little history
The first charge card, which you had to pay off in full every month and which worked at the many restaurants and shops that signed up for it, came from Diners Club in 1950. Later that decade a bank in California began issuing a card that let people carry a balance from month to month. That was the start of the modern credit card.5
FAQ
How do credit cards work for beginners?
A credit card lets you borrow money from a bank to pay for things now and pay it back later. The bank sets a credit limit, the most you can borrow at once. Each month you get a statement. If you pay the whole balance by the due date, on most cards you pay no interest on purchases. If you pay less, the bank charges interest on what's left.
What is the minimum payment on a $500 credit card balance?
Each card company sets its own minimum, so check the statement. It's usually a small part of the balance. Paying only a small amount stretches the debt out: at a 22% APR, paying $10 a month on $500 would take over 10 years and cost about $770 in interest. Paying $50 a month clears it in under a year with about $46 of interest.
How much should I spend if my credit limit is $1,000?
Only what you can pay back in full by the due date. The limit is how much the bank will lend you, not money you have. Credit scores also look at how much of your available credit you're using, so staying well below the limit helps.
How do credit card companies make money?
Mostly in three ways: interest from people who carry a balance, interchange fees that shops pay on each card sale (usually about 1 to 3 percent), and fees such as annual fees and late fees. In 2022, U.S. card companies charged more than $105 billion in interest and more than $25 billion in fees, according to the CFPB.
What are the disadvantages of a credit card?
High interest rates if you don't pay in full, debt that grows because of compound interest, fees such as late fees, a lower credit score if you pay late, and the temptation to spend money you don't have yet.
What's the difference between a credit card and a debit card?
A credit card borrows the bank's money, which you pay back later, with interest if you don't pay in full by the due date. A debit card is linked to your checking or savings account and spends your own money, so there's no interest charge.
Do you pay interest if you pay your credit card in full?
On most cards, no. If your card has a grace period and you pay the full statement balance by the due date every month, you avoid interest on purchases. Cash advances usually start charging interest right away.
Sources
- Consumer Financial Protection Bureau, What is a grace period for a credit card?
- CFPB, What is a credit card interest rate? What does APR mean?
- Federal Trade Commission, Using Credit Cards and Disputing Charges
- FDIC, Debit, Credit and Prepaid Cards: There Are Differences
- Federal Reserve Bank of Richmond, The Role of Interchange Fees on Debit and Credit Card Transactions
- Federal Reserve Board, Who Pays for Your Rewards? (FEDS 2023-007)
- Federal Reserve, G.19 Consumer Credit (release of September 8, 2026)
- CFPB, How does my credit card company calculate the interest I owe?
- CFPB, Credit cards key terms
- CFPB, Credit card companies charged a record $130 billion in interest and fees in 2022
- CFPB, Credit card late fee penalties (2022 report)
- CFPB, What is a credit score?
- MyMoney.gov, Borrow
- CFPB, Your Money, Your Goals: Want credit to work for you?
- CFPB Supervision and Examination Manual, credit card periodic statement rules (Regulation Z)
- Federal Reserve Bank of Boston, Credit History: The Evolution of Consumer Credit in America
- FDIC Consumer News, Using the right card
- Federal Reserve Bank of Boston, Public Policy Discussion Paper 11-4
- CFPB, Credit Card Late Fees and Late Payments (2022 notice)
- CFPB, credit card late fee rule announcement (2024)