Why it happens
- An employee reused card details from a valid sale.
- Extra charges were processed after the cardholder left.
Mastercard4840Fraud
Fraudulent Processing of Transactions
The cardholder took part in one valid purchase, but says other charges were then made on the card without their permission by the same merchant.
What to send to fight it
- Proof the cardholder took part in each disputed transaction, such as signed receipts or separate orders.
- Records showing each charge was a distinct purchase.
- Proof a refund or reversal was already processed.
How to prevent it
- Limit staff access to card data and log who processes each charge.
- Review unusual repeated charges on the same card.
Summaries written by NoChurn from the networks’ public rules and processor documentation. Networks update their rules and deadlines depend on your processor: check its documentation before you respond.
Other Mastercard codes
- 4808Authorization-related Chargeback
- 4837No Cardholder Authorization
- 4849Questionable Merchant Activity
- 4863Cardholder Does Not Recognize—Potential Fraud
- 4870Chip Liability Shift
- 4871Chip/PIN Liability Shift
- 4834Point-of-Interaction Error
- 4831Transaction Amount Differs
- 4842Late Presentment
- 4846Correct Transaction Currency Code Not Provided
- 4853Cardholder Dispute
- 4854Cardholder Dispute—Not Elsewhere Classified (U.S. Region Only)
- 4841Cancelled Recurring or Digital Goods Transactions
- 4855Goods or Services Not Provided
- 4859Addendum, No-show, or ATM Dispute
- 4860Credit Not Processed
- 4999Domestic Chargeback Dispute (Europe Region Only)
Sources (1)
- Mastercard Chargeback Guide, Merchant Edition (19 May 2026) · checked 2026-11-09
Read https://www.nochurn.sh/llms.txt,
then follow https://www.nochurn.sh/docs/quickstart/
to add NoChurn to this app. Use a test key
(nc_test_…) until I say we go live.
Stop leaking revenue.
- Free until $300 MRR
- No card needed
- Live in 10 minutes
- Never a cut of what we recover