Unauthorized Transaction

An unauthorized transaction is a charge the cardholder says they did not authorize or participate in. It is the core claim behind most fraud disputes: the customer contacts their issuer, states that the transaction was not theirs, and the issuer reviews the assertion under the applicable fraud dispute condition and the facts of the transaction.

Importantly, the claim is a starting point rather than a conclusion. Some unauthorized-transaction claims reflect real third-party fraud — a stolen card, a compromised account, or credentials confirmed through card testing. Others are ultimately friendly fraud or first-party misuse, where the cardholder or an authorized user did in fact take part in the purchase. The dispute rules exist precisely to sort these situations out, and the outcome depends on the evidence each side can present.

For merchants, unauthorized-transaction claims call for two kinds of work. The first is prevention: strong authentication, fraud screening, and clear records reduce how often genuine fraud slips through and give the merchant proof of legitimacy when a valid customer disputes a real purchase. The second is disciplined review: examining authentication data, delivery details, and account history before deciding whether to accept the loss or contest the dispute. Handling these claims carefully protects revenue while still treating true fraud victims appropriately.

Unauthorized-transaction claims sit at the center of fraud disputes. How a merchant prevents, detects, and documents these transactions affects both its losses and its fraud reporting.

Because some of these claims are valid and others are not, handling them accurately protects revenue while treating genuine fraud victims fairly.

A cardholder asserts they did not authorize a charge, and the issuer reviews the claim under the applicable fraud dispute condition. The merchant may respond with evidence — authentication data, delivery records, or transaction history — where the facts support the sale.

Strong authentication and screening reduce how often truly unauthorized transactions occur in the first place.

An unauthorized-transaction claim is not automatically valid. It must be reviewed against the applicable dispute rules and the specific transaction facts, because some claims reflect genuine third-party fraud while others turn out to be friendly fraud or first-party misuse. Merchants should evaluate authentication, delivery, and account evidence before deciding whether to accept or contest the claim.