Credit cards can cost you hundreds or even thousands of dollars when used carelessly. The most expensive mistakes involve paying high interest unnecessarily, damaging your credit score, and racking up hidden fees on transactions better handled with cash or a debit card. Here’s what to avoid.
Paying Only the Minimum Each Month
Minimum payments are designed to keep you in debt as long as possible. Each month, your payment covers interest first, and whatever is left chips away at your actual balance. On a card with a 22% APR, a $7,000 balance paid at the minimum could take well over a decade to clear, with thousands of dollars going to interest alone.
To see the difference in real numbers: Bankrate’s payoff calculator shows that increasing your monthly payment on a similar balance to $359 would pay it off in 24 months, with total interest of about $1,632. At the minimum, you’d pay many times that in interest over a much longer timeline. If you carry a balance, pick a payoff target date and work backward to a fixed monthly payment that gets you there. Treating the minimum as your actual payment amount is one of the most costly credit card habits you can have.
Maxing Out Your Cards
Using all or most of your available credit hurts your score significantly. Your credit utilization ratio, the percentage of your total credit limit you’re currently using, is one of the heaviest factors in your FICO score. Someone with a 793 score who maxes out their cards can see their score plunge to the 665-685 range, a drop of more than 100 points. Even someone with a lower starting score loses ground.
A good rule of thumb is to keep your utilization below 30%, and under 10% if you want the best possible score impact. If you have a $10,000 total credit limit across all cards, try to keep your combined balances under $3,000 at any given time. If you regularly bump up against your limit, request a credit limit increase or spread purchases across cards to keep individual utilization low.
Missing Payments
A single missed payment does more damage to your credit than almost anything else. According to FICO score simulations, a person with a 793 score who misses a payment by just 30 days can see their score drop to the 710-730 range. Miss by 90 days, and it falls to 660-680. The higher your score before the miss, the harder the fall, because a clean credit history means one blemish stands out more.
Late payments also trigger fees, typically $30 to $40 per occurrence, and can result in a penalty APR that’s significantly higher than your normal rate. Set up autopay for at least the minimum amount so you never miss a due date, even if you plan to pay more manually each month.
Taking Cash Advances
Cash advances are one of the most expensive ways to use a credit card. The typical fee is 5% of the amount you withdraw, so pulling $1,000 from an ATM with your credit card costs you $50 immediately. On top of that, cash advances carry a higher interest rate than regular purchases, and there’s no grace period. Interest starts accruing the moment you take the money out, not at the end of your billing cycle.
Some transactions you might not realize count as cash advances include buying lottery tickets, sending money through wire transfer services, and purchasing cryptocurrency. Check your card’s terms before making unusual transactions. If you need cash in a pinch, almost any other option, including a personal loan or even an overdraft on your checking account, will cost less than a credit card cash advance.
Paying Rent, Mortgage, or Taxes by Card
Certain large, recurring expenses come with convenience fees when paid by credit card, effectively raising the cost of the bill itself. Mortgage servicers and landlords who accept credit cards often charge processing fees of 2% to 3%. On a $2,000 rent payment, that’s $40 to $60 extra every month for no benefit beyond the transaction itself.
Tax payments work the same way. The IRS and state tax agencies that accept cards pass along processing fees, which can add up fast on a large tax bill. And if you can’t pay off that tax charge immediately, you’re now paying credit card interest rates on it, which are far higher than the payment plan rates that tax authorities themselves offer. Utility companies sometimes charge similar convenience fees. Unless you’re earning enough in card rewards to more than offset these charges (and you pay the balance in full), use your bank account for these bills.
Closing Old Credit Cards
Canceling a credit card you no longer use seems tidy, but it can quietly hurt your credit in two ways. First, closing a card reduces your total available credit, which pushes your utilization ratio higher even if your spending stays the same. If you have $20,000 in total credit across three cards and close one with a $7,000 limit, your available credit drops to $13,000, and the same $3,000 balance that was 15% utilization is now 23%.
Second, closed accounts in good standing stay on your credit report for up to 10 years, but once they fall off, your average account age drops. If the card you closed was your oldest, your credit history suddenly looks shorter, which can lower your score. A better approach: keep the card open, use it for a small recurring charge like a streaming subscription, and set it to autopay. That keeps the account active without requiring you to think about it.
Lending Your Card to Others
When someone else uses your credit card, you’re responsible for every charge they make. This is true whether it’s a friend, a family member, or a partner. If they overspend, miss the repayment they promised, or make purchases you didn’t expect, the balance, the interest, and any credit score damage land entirely on you. Card issuers hold the account holder liable regardless of who physically swiped the card.
If you want to help someone build credit or give them spending access, adding them as an authorized user is a more controlled option. You can set spending limits on some cards, and you can remove an authorized user at any time. But even then, you remain financially responsible for their charges.
Ignoring Your Statements
Fraudulent charges, billing errors, and forgotten subscriptions all show up on your monthly statement, but only if you actually read it. Federal law gives you 60 days from the statement date to dispute unauthorized charges. After that window closes, you may be stuck with them. Reviewing your statement each month also helps you catch subscription services you forgot to cancel and spot whether a promotional 0% APR period has ended, which could mean you’re suddenly paying 20% or more on a remaining balance.
Most card issuers offer real-time transaction alerts through their app. Turning those on gives you an immediate heads-up any time your card is used, making it much easier to catch fraud early and stay aware of your spending without waiting for the monthly statement.