Sample response Codes obtainable are below. Note that this list is not exhaustive.
| S/N | Response Code | Response description |
| 1 | E10 | The service field tag has not been populated. Please ask Interswitch Support for more help. |
| 2 | E11 | This requests expects a transactionType field to be set and it is not. Please ask Interswitch Support for more help |
| 3 | E12 | SecurityToken header is missing. |
| 4 | E13 | Username or password is wrong. |
| 5 | E14 | Missing content type header. |
| 6 | E15 | The transaction you are trying to do is not supported |
| 7 | E16 | The service you have specified is not available |
| 8 | E17 | The service provider you have specified has not been set up on the platform. |
| 9 | E18 | The service is unreachable at the moment |
| 10 | E19 | A bad response was received from service provider |
| 11 | E20 | Your request has timed out |
| 12 | E21 | An unknown error has occurred. Please ask Interswitch Support for more help. |
| 13 | E22 | Access key has not been supplied. Ensure the Authorization header has been set appropriately. |
| 14 | E23 | Nonce has not been supplied. Ensure the Nonce header has been set appropriately. |
| 15 | E24 | Please synchronize your time with the server and ensure your time is not outside of 30mins of the Server local time. The standard time zone used is GMT |
| 16 | E25 | Nonce has already been used |
| 17 | E26 | Signature failed for this request. Please ask Interswitch Support for more help. |
| 18 | E27 | An unknown error occured during Authentication. Please ask Interswitch Support for more help. |
| 19 | E28 | Your credentials do not have access to this resource |
| 20 | E29 | Timestamp is missing in your header |
| 21 | E30 | SecurityToken header is bad. |
| 22 | E31 | XML data is badly formatted |
| 23 | E32 | JSON data is badly formatted |
| 24 | E33 | Keystore is not accessible. Contact Interswitch. |
| 25 | E34 | The system is busy at the moment, please try again later. |
| 26 | E35 | Bad request to service provider. Contact Interswitch. |
| 26 | E36 | Bad request to service processor. Contact Interswitch. |
| 27 | E37 | Bad request from client. Kindly check your message. |
| 28 | E38 | Bad response from service provider. Contact Interswitch. |
| 29 | E39 | Bad response from service processor. Contact Interswitch. |
| 30 | E40 | Bad response to client. Contact Interswitch. |
| 31 | E41 | Bad request from client. Kindly check your message. |