CSC Response Codes
Card security code (CSC) is a security feature that protects against fraud. It ensures that credit card transactions can't be made without it being in the cardholder's possession.
CSC Response Codes
| Response Code | Message |
| M | The CSC matches the issuing bank’s records |
| N | The CSC does not match the issuing bank’s records |
| P | The CSC was not processed |
| S | The card should have a CSC, but merchant indicated it was not present |
| U | Card issuing bank does not participate |
| X | Unknown / No response |