To take advantage of the law's consumer protections, you must:

Write to the creditor at the address given for "billing inquiries," not the address for sending your payments, and include your name, address, account number, and a description of the billing error. Use our sample letter.

Send your letter so that it reaches the creditor within 60 days after the first bill with the error was mailed to you. It’s a good idea to send your letter by certified mail; ask for a return receipt so you have proof of what the creditor received. Include copies (not originals) of sales slips or other documents that support your position. Keep a copy of your dispute letter.

The creditor must acknowledge your complaint, in writing, within 30 days after receiving it, unless the problem has been resolved. The creditor must resolve the dispute within two billing cycles (but not more than 90 days) after getting your letter.

...


If the creditor's investigation determines the bill is correct, you must be told promptly and in writing how much you owe and why. You may ask for copies of relevant documents. At this point, you'll owe the disputed amount, plus any finance charges that accumulated while the amount was in dispute. You also may have to pay the minimum amount you missed paying because of the dispute.

If you disagree with the results of the investigation, you may write to the creditor, but you must act within 10 days after receiving the explanation, and you may indicate that you refuse to pay the disputed amount. At this point, the creditor may begin collection procedures. However, if the creditor reports you to a credit reporting company as delinquent, the report also must state that you don't think you owe the money. The creditor must tell you who gets these reports. The creditor also must promptly report any subsequent resolution of the reported delinquency, to everyone who got a report.

Any creditor who fails to follow the settlement procedure may not collect the amount in dispute, or any related finance charges, up to $50, even if the bill turns out to be correct. For example, if a creditor acknowledges your complaint in 45 days — 15 days too late — or takes more than two billing cycles to resolve a dispute, the penalty applies. The penalty also applies if a creditor threatens to report — or improperly reports — your failure to pay during the dispute period.