A charge you do not recognize shows up on your statement. Your stomach drops. Before you do anything else, it helps to know what the law says you can be asked to pay. The Consumer Financial Protection Bureau (CFPB) publishes plain-language answers on this, and its guidance draws a clear line between lost cards, stolen account numbers, and cards you handed to someone else.
When You Can Be Held Responsible
Timing matters most when a card goes missing. If you report a lost or stolen card before anyone uses it, you cannot be held responsible for unauthorized charges, according to the CFPB.
Unauthorized use generally means use of a card by someone who has no right to use it. If you lose a card and a stranger finds it and runs up charges, that counts, per the CFPB's explanation of unauthorized use.
If the misuse happens before you report the card missing, the most you will owe is $50. That cap applies no matter how quickly you later dispute the charges. The CFPB also notes that many cardholder agreements say you owe nothing in this situation. Your own agreement is where to check. You can usually find it on the card company's website, or in the CFPB's Credit Card Agreement Database.
Stolen Account Numbers and Shared Cards
A stolen account number is a different case from a lost card. If someone steals and uses your account number while you still hold the physical card, you generally have no liability for that use, according to the same CFPB guidance on lost or stolen cards.
Sharing a card changes the picture. If you give your card to someone, you have authorized that use. If that person spends the money for a different purpose than you intended, the CFPB says it may still count as authorized. You stay responsible for their charges until you tell the card issuer that the person is no longer authorized. The issuer may then issue a new card.
The sources do not say how to word that notice or whether the issuer needs it in writing. Asking your issuer how it wants to receive the request is a sensible step. Keeping a note of the date you made it is a practical habit, though the CFPB pages do not require it.
A short question can sort out most cases:
- Did you report the card before anyone used it?
- Was only the account number stolen?
- Did you ever give the person permission to use the card?
How to Dispute a Charge in Writing
For a billing error, the CFPB's dispute guidance gives two steps. Call the card company and report the problem right away. Then send a written billing error notice.
The deadline is firm. To protect your rights in a billing dispute, send the written notice within 60 calendar days after the charge appeared on your statement. That 60-day window applies to billing disputes, not to the $50 cap described above.
After the company receives your written notice, it has 30 days to send a letter confirming receipt. The exception is when it has already finished the required billing error resolution steps within that time.
The CFPB page does not say where to mail the notice or what it must contain. Your card agreement or the billing statement itself is the likeliest place to find the issuer's instructions. Keep copies of everything. Write down the dates of follow-up calls and keep them in one file.
Call right away. Then put it in writing.
What Happens After a Dispute
If the company finds you are correct, the charge must be removed from your bill. If it finds the bill is correct, it must explain why in writing. That letter also has to tell you how much you owe and when payment is due.
You can still dispute a charge you have already paid. You probably will not get the money back until the card company decides you were right.
Some disputes follow a different path. The CFPB notes that complaints about defective goods or services may be handled by a different process.
The sources leave real gaps here. They do not explain what to do if the issuer rejects your dispute beyond the written explanation. They do not say how long an investigation may take. They also do not say how a disputed charge affects your credit report or score. Those are fair questions to put to your issuer directly.
Debit and ATM cards fall under a separate rule, Regulation E, which implements the Electronic Fund Transfer Act and covers consumer liability for unauthorized transfers in section 1005.6. The sources here do not spell out its liability tiers or deadlines, so check the CFPB's Regulation E pages before assuming credit card rules apply to a debit card.
The practical sequence is short. Check your agreement. Call the issuer. Send the written notice inside 60 days. Keep the file.
