Why it happens
- A transaction was submitted twice.
- A retry ran after the first payment had already succeeded.
DiscoverDPProcessing error
Duplicate Processing
The cardholder says the same transaction was charged more than once.
What to send to fight it
- Records showing each charge was a separate purchase or billing period.
- Invoices or receipts for each charge.
- Proof a true duplicate was already refunded.
How to prevent it
- Check for a successful payment before retrying.
- Use a unique reference for each charge.
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 Discover codes
- AADoes Not Recognize
- APCancelled Recurring Transaction
- AWAltered Amount
- CDCredit/Debit Posted Incorrectly
- ICIllegible Sales Data
- NFNon-Receipt of Cash from ATM
- PMPaid by Other Means
- RGNon-Receipt of Goods, Services, or Cash
- RMQuality Discrepancy
- RN2Credit Not Received
- UA01Fraud - Card Present Transaction
- UA02Fraud - Card Not Present Transaction
- UA05Fraud - Chip Counterfeit Transaction
- UA06Fraud - Chip and PIN Transaction
- 4534Duplicate Processing
- 4537Fraud - Card Present Transaction
- 4542Late Presentation
- 4550Credit/Debit Posted Incorrectly
- 4553Cardholder Disputes Quality of Goods or Services
- 4586Altered Amount
- 4752Does Not Recognize
- 4753Invalid Cardholder Number
- 4755Non-Receipt of Goods or Services
- 4863Authorization Non-Compliance
- 4864Non-Receipt of Cash from ATM
- 4865Paid by Other Means
- 4866Fraud - Chip Card Counterfeit Transaction
- 4867Fraud - Chip Card and PIN Transaction
- 4868Fraud - Card Not Present Transaction
Sources (2)
- TabaPay Docs: Discover chargeback reason codes · checked 2026-11-09
- Antom (Alipay) Docs: Discover/Diners dispute reason codes · 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