What a rewards credit card does
A rewards credit card returns a percentage of what you spend back to you in the form of points, miles, or cash. The card issuer pays you this rebate because they earn money from the merchant fees charged every time you swipe. You are not paying extra for the purchase — the merchant fee exists whether you use a rewards card or not.
The most common structure is cash back, where you earn 1% to 5% of your spending depending on the category. Some cards earn flat-rate cash back on all purchases. Others earn higher percentages on specific categories like groceries, gas, or dining, and lower rates on everything else. A second type offers points or miles that you redeem for travel, gift cards, or merchandise — these are worth less per dollar spent than cash back, but appeal to people who want to save toward a specific trip or goal.
The catch is that most rewards cards charge an annual fee, ranging from $0 to $700 or more. A card that earns 2% cash back but costs $95 per year only makes financial sense if you spend enough to earn at least $95 in rewards. If you spend $5,000 per year, you earn $100 in cash back — a net gain of $5. If you spend $2,000 per year, you earn $40 and lose $55.
Key Takeaways
- Rewards cards return 1% to 5% of your spending as cash, points, or miles, funded by merchant fees, not by charging you more.
- An annual fee only makes sense if your annual rewards earnings exceed the fee amount — calculate this before you open the card.
- Introductory bonus categories (like 5% back on groceries for the first year) often drop to 1% or lower after the promotional period ends.
- Carrying a balance and paying interest erases rewards value when ready — a 2% cash back card becomes a net loss if you pay 20% interest on the balance.
- Some cards restrict redemption options or impose minimum redemption amounts, so read the terms before you assume your points are flexible.
Annual fees and when they make sense
A no-annual-fee card is the safest choice if you are not certain you will use the rewards. These cards typically earn 1% to 2% cash back on all purchases, or 1% to 3% in rotating categories. You break even at any spending level, because there is no fee to overcome.
A card with an annual fee makes sense only if you spend enough to earn more in rewards than the fee costs. A $95 annual fee card that earns 2% cash back requires $4,750 in annual spending to break even ($95 ÷ 0.02 = $4,750). If you spend $10,000 per year, you earn $200 in cash back and net $105 after the fee. If you spend $3,000 per year, you earn $60 and lose $35.
Many premium cards offer a sign-up bonus — for example, $200 cash back after you spend $500 in the first three months. This bonus counts toward your first-year value. A card with a $95 fee and a $200 sign-up bonus is worth keeping for one year if you meet the spending requirement, even if you would not normally earn enough rewards to justify the fee. After year one, decide whether to keep it based on your actual spending.
How introductory rates and category changes work
Many rewards cards advertise a high cash back rate for a limited time — for example, 5% back on groceries for the first year, then 1% after that. This is a marketing tool to get you to open the card. The introductory rate is real, but it expires. You need to know the permanent rate before you decide whether the card is worth keeping.
Some cards rotate bonus categories quarterly — for example, 5% back on a different category each three months (groceries one quarter, gas the next, restaurants the next). You have to set up each category when it becomes active, or you earn the base rate instead. If you forget to set up, you lose the bonus for that quarter. Check whether the card sends reminders or whether you have to track the calendar yourself.
Read the terms carefully to see whether the introductory bonus applies to new cardholders only, or whether existing cardholders can earn it again. Some cards let you earn the sign-up bonus once per lifetime; others allow it once per year if you close and reopen the card.
Interest charges and how they erase rewards
A rewards card is only valuable if you pay the full balance every month. If you carry a balance, you pay interest — typically 18% to 25% annually — on the amount you owe. A 2% cash back card becomes a net loss when ready.
Here is the math: if you spend $1,000 and earn $20 in cash back, but carry the balance and pay $200 in interest over the year, you have lost $180. The rewards do not offset the interest. This is true even on premium cards that earn 5% cash back. The interest rate is always higher than the rewards rate.
If you have a history of carrying balances, a rewards card is not the right tool. A card with a 0% introductory APR on purchases (usually 6 to 21 months, depending on the card) is more useful, because it lets you pay down debt without interest charges. Once the introductory period ends, the regular APR kicks in, so you still need a plan to pay off the balance.
Points and miles versus cash back
Points and miles cards earn rewards in a currency that is not dollars. You redeem points for travel bookings, gift cards, merchandise, or statement credits. The value of a point varies depending on how you redeem it. A card might say your points are worth 1 cent each, but if you redeem them for a gift card, you might get only 0.8 cents per point. If you redeem them for a travel booking through the card's portal, you might get 1.5 cents per point.
This flexibility is appealing if you have a specific goal — saving toward a vacation, for example. But it also means the card's true value depends on how you use the points. If you never redeem them, they are worthless. If you redeem them poorly — for example, buying merchandise at 0.5 cents per point when you could get 1.5 cents per point on travel — you lose value.
Cash back is simpler: you earn a percentage of your spending back as dollars, and you can use those dollars however you want. A 2% cash back card is worth 2% no matter what. A points card that advertises "2 points per dollar" might be worth 1% or 3% depending on redemption, so you have to read the fine print.
Spending categories and how they work
Many rewards cards offer higher cash back in specific categories — groceries, gas, dining, travel, or online shopping — and a lower rate on everything else. The card issuer chooses these categories based on where they expect high spending. You earn the bonus rate only when you use the card in that category.
Some cards define categories narrowly. "Gas" might mean gas stations only, not convenience stores or car washes. "Groceries" might mean supermarkets but not warehouse clubs or farmers markets. Check the card's terms to see how the issuer defines each category, because the merchant's classification determines which rate you earn. If you buy groceries at a warehouse club and the card does not count warehouse clubs as groceries, you earn the base rate instead.
Rotating-category cards require you to set up each category when it becomes active. If you forget, you earn the base rate for that quarter. Set a phone reminder when a new quarter begins, or check the card's website or app at the start of each month to see which category is active and set up it if needed.
How to choose between cards
Start by calculating your annual spending in each category — groceries, gas, dining, travel, and everything else. Then compare the rewards you would earn on each card against the annual fee.
If you spend $8,000 on groceries, $3,000 on gas, $2,000 on dining, and $5,000 on everything else, a card that earns 3% on groceries, 2% on gas, 1% on dining, and 1% on everything else would earn: ($8,000 × 0.03) + ($3,000 × 0.02) + ($2,000 × 0.01) + ($5,000 × 0.01) = $240 + $60 + $20 + $50 = $370 per year. If the card has no annual fee, you keep all $370. If it has a $95 annual fee, you net $275.
Compare this to a flat-rate no-annual-fee card that earns 2% on all spending: $18,000 × 0.02 = $360 per year. The category card earns $10 more, but only if you remember to use it in the right categories and set up rotating bonuses. If you forget, the flat-rate card is simpler and nearly as valuable.
If you travel frequently or have a specific redemption goal, a points or miles card might be worth the complexity. If you want simplicity and certainty, a flat-rate no-annual-fee card is the better choice.
Frequently Asked Questions
Does using a rewards card hurt my credit score?
Opening a new card temporarily lowers your score because the issuer runs a hard inquiry and you have a new account with no history. The score usually recovers within a few months. Using the card and paying the balance in full actually helps your score over time, because it shows you can manage credit responsibly and lowers your credit utilization ratio.
Can I earn rewards on balance transfers or cash advances?
No. Rewards explore only to regular purchases. Balance transfers and cash advances do not earn points or cash back, and they usually carry a separate fee (typically 3% to 5% of the amount transferred or withdrawn). Some cards also charge a higher interest rate on these transactions.
What happens to my rewards if I close the card?
This depends on the issuer. Most cards let you keep your rewards balance after you close the account, and you can redeem it for cash, points, or miles. Some cards expire rewards after a period of inactivity, so check the terms before you close. If you have a small rewards balance that is not worth redeeming, ask the issuer whether you can transfer it to another card you own from the same company.
Do I have to use the card every month to keep the rewards?
No. Rewards do not expire based on how often you use the card. They expire based on account inactivity — usually if you do not make any purchase for 12 to 24 months, the issuer may close the account and forfeit the rewards. To keep the account active, make at least one small purchase every year or two.
What if the card's rewards rate changes after I open it?
The issuer can change the rewards rate on future purchases, but they cannot change the rate on purchases you have already made. If you disagree with the change, you can close the card without penalty. You keep the rewards you have already earned. Some issuers notify cardholders before a rate change and give you time to close the account if you do not like the new terms.