If you are looking for Sandbox error codes or Fiserv error codes please refer to this link
| CODE | Text String | Comment |
| 00 | Approval | Approved and completed. |
| 01 | Call | Refer to issuer. |
| 02 | Call | Refer to issuer—Special condition |
| 03 | Term ID Error | Invalid Merchant ID |
| 04 | Hold-call | Pick up card (no fraud) |
| 05 | Decline | Do not honor |
| 06 | Error XXXX | General Error. |
| 07 | Hold-call | Pick up card, special conditions (Fraud account) |
| 10 | Partial Approval | Partial approval for authorized amount. |
| 12 | Invalid Transaction | |
| 13 | Amount Error | Invalid Amount. |
| 14 | Card No. Error | Invalid card number. |
| 15 | No such issuer | No such issuer of the credit card. |
| 19 | Re ENTER | Re-enter transaction. |
| 39 | No Credit Acct | No Credit Account. |
| 41 | Hold-call | Lost card, pick up card (fraud account). |
| 43 | Hold-call | Pick up card, stolen card, pick up (fraud account). |
| 51 | Decline | Insufficient funds. |
| 54 | Expired card | Expired card—different than invalid expiration date. |
| 57 | Service not allowed | Transaction not permitted on card. |
| 58 | Service not allowed | Service not allowed. Transaction not permitted—Terminal. |
| 59 | Service not allowed | Service not allowed. Transaction not permitted—Merchant. |
| 61 | Declined | Exceeds withdrawal limit. |
| 62 | Declined | Invalid service code, restricted. |
| 63 | Sec Violation | Security violation. |
| 65 | Declined | Activity limit exceeded. |
| 77 | No Action taken | Inconsistent data, reversed or repeat. |
| 79 | Already Reversed | Already reversed at switch. |
| 80 | No impact | No financial impact (used in responses for declined originals). |
| 82 | Incorrect CVV | CVV data not correct. |
| 85 | Card OK | No reason to decline. |
| 93 | Decline violation | Cannot complete. |
| 94 | Duplicate Trans | Unable to locate, no match. |
| 96 | System Error | System malfunction. |
| CV | Failure CV | Card Type verification error. |
| EC | CID format error | Verification error. |
| HV | Failure Hierarchy | Verification error. |
| N4 | Decline | Exceeds Issuer withdrawal limit. |
| N7 | CCV2 mismatch | CVV2 value supplied is invalid. |
| R0 | Stop recurring |
Customer requested stop of specific recurring transactions. |