The credit card application and marketing materials come with a thing called "Shummer Box": a chart that tells you the most important information about a credit card. Here's how to read the details of the Schumer box.

Purchase: This is the interest rate charged for things you didn't pay off the previous month. It is charged on a daily basis - that is, if your annual interest rate is 15%, you will not charge 15% of the annual fee, but will charge 0.0027% per day. Some credit cards will give you a 0% introduction period of 6 months or longer, allowing you to develop the habit of using a credit card. With these offers, you can make a big purchase and pay interest for free for a while.

Variable interest rate: If Schumer Box says that your interest rate is “variable” (probably variable), it means that your interest rate is related to a base rate called the prime rate. The base rate is controlled by the Federal Reserve. If the preferential interest rate rises by 0.25% or 1% or other amount, your credit card interest rate will also rise.

Transfer: If you have credit card debt, you can change to a new one. Some credit cards allow you to transfer your debts, and you don't pay interest for 6 to 12 months, but other credit cards charge at the normal rate of purchase.

Prepaid cash: If you take out a prepaid cash (that is, if you use your card to withdraw cash from an ATM or withdraw money from a bank teller), you will be charged the amount you borrowed. Unlike regular purchases, if you have a grace period to pay off your debt, you can start accruing interest on the day you receive the prepaid cash.

Penalty: If you missed the payment, you may have to pay this higher interest rate for up to six months.

"How to avoid paying interest"

This section tells you your grace period, or how long it takes you to repay your debt after the credit card statement date without generating interest.

Minimum interest expense

If you owe any interest, at least this amount. So, if you hold a $1 balance and your interest rate is 12.99%, you will usually be charged $0.01, but the credit card company will raise it to $0.50.

Annual fee

It sounds like this. You pay the credit card company to carry their products. Most credit cards do not have an annual fee, but they are common on credit cards that offer high returns. For people with a bad or bad credit situation, credit cards are also more likely to be charged.

Transaction fee

Transfer fee: If you transfer debt from one card to another, you will usually be transferred to another card. The fee is usually between 3% and 5% of the transfer amount. Several cards do not charge the transfer fee.

Prepaid cash: If you make a prepaid cash, you will pay the fee on the basis of the immediate accrual of interest.

Foreign transaction fees: If you use a credit card abroad, you will be charged this time each time you purchase it abroad. Foreign exchange transactions are usually about 3% of the purchase. Most credit cards for travellers do not charge this fee, and some card issuers (especially Capital One and Discover) do not charge any credit card fees.

Penalty fee

Late payment: If you do not pay at least the minimum amount due before the expiration date on your credit card statement, you must pay this fee. If you are late for more than 30 days, it may affect your credit score.

Excess Fee: If you exceed your credit limit, the issuer can still approve the transaction, but you will be charged this fee. However, you must choose over-insurance before you can choose over-insurance. Because of this, overcharging is now rare.

Return Payment: If you attempt to pay your credit card bill, but for some reason (such as a check being returned or bank transfer is denied), you must pay this fee.

Reward plan details

If you have a reward credit card, this section will detail how you earn and redeem rewards. Read this section carefully. Many credit card reward programs are great, giving you cash or points and you can redeem for free travel. But others aren't everything they do -- paying a negligible fee, or rewarding you only for piecemeal items you don't want or gift cards that you never use.