🏷️ Reason codes

What a reason code does

The reason code is the standardized reason the issuer attaches to a chargeback when it files it. It drives everything that follows. It determines the acceptable evidence for representment, the applicable deadlines, which Visa workflow applies (allocation or collaboration), and how the case is routed internally to the right team. A representment built for the wrong code will be rejected, however strong the evidence.

• Operational routing: a 10.4 (card-not-present fraud) goes to the fraud/3DS team, and a 13.1 (not received) goes to the logistics team.
• Required evidence: each code has its own list of acceptable documents in the scheme rulebooks (Visa Core Rules, Mastercard Chargeback Guide).
• Monitoring: programs count fraud differently (VAMP adds TC40 fraud reports to all TC15 disputes, fraud disputes included; Mastercard tracks chargebacks in ECM and fraud in EFM), and the mix of codes drives the merchant's exposure.
• Product signal: a rise in 13.3s (not as described) points to a quality problem, not a fraud problem.

Visa: the VCR taxonomy

Since Visa Claims Resolution (VCR) launched in 2018, Visa has grouped its codes into four families. 10.x and 11.x follow the allocation workflow, where liability is assigned automatically by rule, including the 3DS liability shift. The merchant responds directly at pre-arbitration. 12.x and 13.x follow the collaboration workflow, which includes a genuine two-sided representment stage.

Mastercard: consolidated codes

Mastercard has consolidated its reason codes on a large scale. Most consumer disputes now fall under 4853, with a detailed sub-reason in the message, and processing errors fall under 4834. The message reason code alone is no longer enough, because the sub-reason is carried in the chargeback data (Mastercom).

CB specifics

CB (Cartes Bancaires) is France's domestic card scheme. It is run by GIE CB, the banks' consortium, which sets its own dispute rules. In France, about two-thirds of transactions on co-badged cards are routed through CB (63.6% in the second half of 2025, according to fintech Yavin’s index), and any dispute then follows CB's rules rather than Visa's or Mastercard's. The cycle works the same way: a chargeback (an impayé in CB terms), then a representment, then arbitration by GIE CB. CB has its own chargeback reasons, covering both fraud (lost or stolen card, counterfeit, fraudulent remote payment) and commercial disputes. Deadlines are in line with international standards: 120 days for most reasons.

• Dispute routing follows transaction routing: a CB/Visa co-badged card used as “CB” opens a CB chargeback, even if the cardholder uses a Visa app. The brand chosen at payment (a cardholder right under the 2015 EU Interchange Fee Regulation, IFR) determines which dispute rules apply.
• 3DS liability shift: CB shifts liability for transactions authenticated through its own 3DS infrastructure. A frictionless transaction under an acquirer TRA exemption leaves fraud liability with the merchant, just as with Visa and Mastercard.
• More interbank processing: documentation requirements are similar, but disputes are resolved more through domestic interbank channels and GIE CB tools. French PSPs usually show CB and international chargebacks in the same standardized interface.
• Structurally low fraud: fraud on domestic CB transactions is among the lowest in Europe, according to France's payment security observatory (OSMP). That means fewer in-person fraud chargebacks, and most of the risk sits in remote sales.

Interpreting codes and routing the response

Dispute handling is configured from the reason code, which acts as a routing instruction. The code identifies the team responsible, the evidence to collect, the break-even threshold, and the upstream fix to put in place. The table below summarizes the standard response for each code family.

{
  "dispute_routing": {
    "10.4": {
      "family": "cnp_fraud",
      "team": "risk",
      "if_3ds_authenticated": "REPRESENT (liability shifted to issuer, attach ECI+CAVV)",
      "if_ce30_eligible": "REPRESENT (2 prior undisputed orders, same device/IP)",
      "else": "ACCEPT if amount < 30 EUR, otherwise manual review"
    },
    "13.1": {
      "family": "not_received",
      "team": "logistics",
      "key_evidence": "tracking + signed or geolocated proof of delivery",
      "if_delivery_proven": "REPRESENT",
      "else": "ACCEPT and refund right away (limits fees)"
    },
    "12.6.1": {
      "family": "duplicate_processing",
      "team": "accounting",
      "action": "check for duplicate; ACCEPT immediately if confirmed",
      "alert": "open a reconciliation incident if > 3 cases / week"
    },
    "4853:credit_not_processed": {
      "family": "credit_not_processed",
      "action": "check that the credit was issued; if not, REFUND at pre-dispute"
    }
  }
}