Prompt Credit for Payment. An issuer must credit your account the day payment is received. The exceptions are if the payment is not made according to the creditor’s requirements, or the delay in crediting your account won’t result in a charge.

To help avoid finance charges, follow the issuer’s mailing instructions. Payments sent to the wrong address could delay crediting your account for up to five days. If you misplace your payment envelope, look for the payment address on your billing statement or call the issuer.

Refunds of Credit Balances. When you make a return or pay more than the total balance at present, you can keep the credit on your account or write your issuer for a refund — if it’s more than a dollar. A refund must be issued within seven business days of receiving your request. If a credit stays on your account for more than six months, the issuer must make a good faith effort to send you a refund.

Errors on Your Bill. Issuers must follow rules for promptly correcting billing errors. You’ll get a statement outlining these rules when you open an account and at least once a year. In fact, many issuers include a summary of these rights on your bills.

If you find a mistake on your bill, you can dispute the charge and withhold payment on that amount while the charge is being investigated. The error might be a charge for the wrong amount, for something you didn’t accept, or for an item that wasn’t delivered as agreed. Of course, you still have to pay any part of the bill that’s not in dispute, including finance and other charges.

If you decide to dispute a charge:

• Write to the creditor at the address indicated on your statement for "billing inquiries." Include your name, address, account number, and a description of the error.
• Send your letter soon. It must reach the creditor within 60 days after the first bill containing the error was mailed to you.

The creditor must acknowledge your complaint in writing within 30 days of receipt, unless the problem has been resolved. At the latest, the dispute must be resolved within two billing cycles, but not more than 90 days.

Unauthorized Charges. If your card is used without your permission, you can be held responsible for up to $50 per credit card.

If you report the loss before the card is used, you can’t be held responsible for any unauthorized charges. If a thief uses your credit card before you report it missing, the most you’ll owe for unauthorized charges is $50.

To minimize your liability, report the loss as soon as possible. Some issuers have 24-hour toll-free telephone numbers to accept emergency information. It’s a good idea to follow-up with a letter to the issuer — include your account number, the date you noticed your card missing, and the date you reported the loss.

Disputes about Merchandise or Services. You can dispute charges for unsatisfactory goods or services. To do so, you must:

• have made the purchase in your home state or within 100 miles of your current billing address. The charge must be for more than $50. (These limitations don’t apply if the seller also is the card issuer or if a special business relationship exists between the seller and the credit card issuer.) and,
• first make a good faith effort to resolve the dispute with the seller. No special procedures are required to do so.

If these conditions don’t apply, you may want to consider filing an action in small claims court.

You’ll probably also want to consider if the credit limit is high enough, how widely the card is accepted, and the plan’s services and features. For example, you may be interested in "affinity cards" — all-purpose credit cards sponsored by professional organizations, college alumni associations and some members of the travel industry. An affinity card issuer often donates a portion of the annual fees or charges to the sponsoring organization, or qualifies you for free travel or other bonuses.

Special Delinquency Rates. Some cards with low rates for on-time payments apply a very high APR if you are late a certain number of times in any specified time period. These rates sometimes exceed 20 percent. Information about delinquency rates should be disclosed to you in credit card applications or in solicitations that do not require an application.