What Mastercard 4870 means
The issuer reports counterfeit fraud on a transaction where the card was a chip card but the merchant's terminal did not perform a chip transaction, shifting liability to the acquirer.
Common causes
- Magnetic stripe-only terminals
- Technical fallback to stripe without proper handling
- Key-entered card-present transactions
Evidence that answers it
- Terminal records showing chip data (DE 55) was provided in the first presentment
- Proof the transaction was a properly identified technical fallback
- Proof of a refund
How to prevent it
- Use EMV chip terminals and replace swipe-only devices
- Investigate frequent fallback transactions
Time limits and caveats
Fraud-related family. Adyen documents that 4870 and 4871 escalate straight to arbitration without a pre-arbitration step. Not relevant to card-not-present e-commerce.
How Verdikx helps with 4870
Verdikx maps 4870 to its fraud playbook. It is a card-present liability-shift code, so for an online store the Shopify order record, showing a web checkout rather than a terminal sale, is the basis for asking your processor whether the case was miscoded.
Frequently asked questions
What does Mastercard reason code 4870 mean?
Mastercard 4870 Chip Liability Shift applies to counterfeit-card fraud on a card-present transaction where a chip card was not processed as chip, for example through magnetic stripe fallback at a terminal that was not chip-capable. The non-chip party bears the loss. It is rarely winnable for merchants without chip-read records.
Is Mastercard 4870 worth fighting?
Our reference rates 4870 (Chip Liability Shift) rarely winnable, so check the facts before spending time on a response. The evidence that answers it starts with terminal records showing chip data (DE 55) was provided in the first presentment. The cardholder's bank decides the outcome.
Answer your next 4870 with the right evidence.
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Sources
- Mastercard Chargeback Guide, Merchant Edition (13 May 2025) (checked October 5, 2026)
- Adyen Docs: Mastercard chargebacks (checked October 5, 2026)
Last reviewed by Verdikx Research.