Credit Cards 101

1. Why the US credit system matters

In the US, your credit history follows you everywhere: apartment applications, car loans, mortgage rates, sometimes even job checks. The system is built on credit cards. Used correctly, they are the cheapest and fastest way to build a strong file, and they pay you in rewards while doing it. Used wrong, the interest erases everything. This tutorial is the correct way.

2. How a credit card actually works

You spend on the card during the month. The statement closes and shows your balance. You then have a grace period, about 21 to 25 days, to pay. Pay the full statement balance by the due date and you pay zero interest, ever. The advertised APR only matters if you carry a balance.

• Rule one: pay the statement balance in full, every month, no exceptions.
• Rule two: autopay for the full balance, so rule one never depends on memory.
• Rule three: the rewards game is only profitable if you obey rules one and two.

3. Building credit from zero

No credit history yet? You have four standard entry doors, and you only need one:

• Secured cards. You deposit a few hundred dollars as your credit line. Use it lightly, pay in full, and most issuers upgrade you to a normal card within a year and return the deposit.
• Student cards. If you are enrolled, the Discover it Student and similar cards approve thin files and still earn rewards.
• Beginner-friendly issuers. Discover and the Chase Freedom Rise are built for first files, and Rise approval odds improve with a small Chase checking balance.
• Authorized user. A parent or partner adds you to an old, clean account and its history lifts your file. Make sure the primary user never carries a balance.

4. What your score is made of

FICO weighs five things: payment history (35%), utilization (30%), age of accounts (15%), credit mix (10%) and new credit (10%). Beginners control the big two from day one: never miss a payment, and keep reported balances low. The full breakdowns live in our credit score guide and utilization guide.

5. The first-year path

• Months 0 to 6: one starter card, small recurring charge, autopay in full.
• Months 6 to 12: score appears and climbs past 700 if you did nothing wrong. Keep going.
• Month 12+: you now qualify for real rewards cards, and the first card you should consider is a no-fee 2% card or, if you travel, the Sapphire Preferred when its bonus runs 75k or better.

Important: never close the starter card. Its age is now an asset. Downgrade it to a no-fee version if it ever carries a fee.

6. Graduating to the rewards game

Once you are above 700 with a year of history, the entire site opens up to you: welcome bonuses worth four figures, transferable points, lounge access. Start with the points and miles beginners guide, check the live bonus rankings, and learn each bank's application rules on the issuer pagesbefore you apply. One rule to know early: Chase's 5/24 means you usually want Chase cards first.

7. The five mistakes that cost beginners years

• Carrying a balance "to build credit". A myth. It builds nothing and costs 25%+.
• Closing your oldest card. You just shortened your history.
• Maxing the card even if you pay in full. High reported utilization dents your score; see the statement-date trick in the utilization guide.
• Applying for five cards in month two. Velocity matters; build first, harvest later.
• Taking cash advances. Different rules, instant interest, never worth it.

8. Quick glossary

• 5/24: Chase's rule against 5+ new cards in 24 months.
• AF: annual fee.
• APR: the interest rate you never pay if you follow rule one.
• ATH: all-time-high offer.
• AU: authorized user.
• FTF: foreign transaction fee.
• PC: product change, switching a card without a new application.
• SUB: sign-up bonus.

See the full acronym glossary