Mastercard Reason Code 4870

A counterfeit chip card was used where liability shifts based on which party supported EMV chip technology.

A fraudulent EMV chip card transaction occurred, and liability shifts to whichever party (merchant or issuer) didn't support chip.

Card-present only — if your checkout is online, this code typically doesn't apply to you directly.

Terminal EMV chip-read confirmation, if the sale was in person.

Running non-EMV-compliant terminals for in-person sales.