Reason codes, and why the evidence that wins depends on them.
Reason codes differ between networks but collapse into four families. Which family you are in decides what evidence has any chance of working, and submitting the wrong kind is the most common way a winnable dispute is lost.
What this page settles.
Three questions, in the order most people ask them.
Why the code matters more than the amount
A dispute notification tells you three things: the transaction, the amount, and a reason code.
Most merchants read the first two.
The code is the one that decides the outcome, because it states what the cardholder has actually claimed. A dispute saying “I never received this” and a dispute saying “this is not what was advertised” are different accusations requiring different proof, and a bundle that comprehensively answers one will not address the other at all.
This is the single most common reason winnable disputes are lost. Not weak evidence — irrelevant evidence, submitted with care, against a claim nobody read.
The four families
Visa and Mastercard use different code sets and both revise them, so there is little point memorising specific codes. What does not change is what a cardholder can actually be claiming, and that collapses into four.
Fraud. “I did not make this transaction.” The card or its details were used by somebody else, or the cardholder says so.
Not received. “I paid and nothing arrived.” Goods not delivered, services not rendered, an order cancelled and still charged.
Not as described, or defective. “I got it, and it is not what I was promised.” Quality, condition, specification, or a service that was not what was sold.
Processing error. Duplicate charge, wrong amount, wrong currency, a recurring payment taken after cancellation, a credit never issued.
Read your notification, decide which of the four it is, and everything else follows.
What wins in each
Fraud. You are proving the legitimate cardholder transacted. For a card-present sale, the terminal record showing the chip was read or the card was tapped is close to decisive — which is why keyed transactions are riskier as well as dearer. For card-not-present, your bundle is address verification result, security code result, 3-D Secure where used, the IP address and device, delivery to the billing address, and any history of the same customer buying from you before.
Not received. You are proving delivery. Tracking showing delivery to the address on the order, signature where you have it, and the date against the claim. For services, the appointment record, the access log, the completed work. Delivery to a different address from the billing address is where most of these are lost.
Not as described. You are proving the customer got what was advertised. Your listing as it appeared at the time, photographs, the specification, your returns policy as published, and your communications with the customer. This family turns on contemporaneous evidence — a listing you have since edited is not evidence of what they saw.
Processing error. You are proving your own records. The authorization and settlement records, the amount, the refund if you issued one and its date. Frequently the honest answer here is that the customer is right, in which case accept it quickly and move on.
One bundle does not fit four accusations. If you are submitting the same pack every time, you are winning only the cases that would have gone your way regardless.
What never wins
Worth being blunt, because a lot of effort goes into these.
“The customer is lying.” Possibly true, and not evidence.
Your terms and conditions, alone. A no-refunds policy does not defeat a not-as-described claim. It can support a bundle; it cannot be one.
A long narrative. The person reading this is working through a queue. Lead with the document that answers the claim.
Evidence of a different transaction. More common than it sounds when a customer has bought several times.
Anything submitted after the deadline. The window is short and counted in days from notification. Missing it loses the case automatically, and a large share of lost disputes are lost exactly this way — the notification went to an address nobody monitors.
Building a bundle that is actually read
Lead with the one document that answers the code. Tracking for non-receipt. Verification data for fraud. The listing for not-as-described.
One page of plain summary at the front. What was bought, when, how it was delivered, and which attachment proves it.
Legible attachments, labelled, in order.
Nothing irrelevant. A thick pack of marginal material buries the thing that wins.
Submit early. Not on the last day.
And the decision before any of it: is this worth fighting? The dispute fee is usually charged either way, so a small amount with thin evidence costs more to contest than to concede. Spend your effort where the evidence is strong, the amount is meaningful, or your ratio is close to a threshold.
Then spend considerably more effort on the thing that actually works, which is not getting the dispute in the first place — a recognisable billing descriptor, a phone number somebody answers, and a fast refund on anything borderline.
What we charge
Interchange + 0.50% + 10¢ in person, interchange + 0.75% + 25¢ keyed, with no contract and no monthly fee. We will tell you our dispute fee before you sign rather than after.
Send us a statement and tell us which codes you are seeing. A pattern in the codes usually points at something specific — a descriptor nobody recognises, a delivery lead time, a subscription that renews quietly — and that is a cheaper thing to fix than a dispute rate.
While we are on the subject
Where do I find the reason code?
On the dispute notification from your processor. It is a short alphanumeric code with a description attached, and both are worth reading rather than skipping to the amount.
Do the codes mean the same thing on Visa and Mastercard?
The codes themselves differ, but they map onto the same four underlying situations. Work out which family you are in and the evidence question answers itself.
Should I fight every chargeback?
No. The dispute fee is usually charged whether you win or lose, so a small disputed amount with weak evidence costs more to fight than to concede. Spend the effort where the evidence is strong or the amount is large.
Does winning remove it from my ratio?
Generally not. The dispute was filed and counted in the month it happened, which is the strongest argument there is for prevention over representment.