# Error codes

The following table lists the error codes that the callbacks may return.

| **Code** | **Constant** | **Description** |
| --- | --- | --- |
| `1001` | `ResultCode.PARAM_ILLEGAL` | Invalid or illegal parameter. |
| `1002` | `ResultCode.INVALID_NETWORK` | Network is unavailable. |
| `1003` | `ResultCode.SYSTEM_ERROR` | Internal system error. |
| `1004` | `ResultCode.USER_CANCEL` | User canceled the operation. |
| `1006` | `ResultCode.USER_DENY` | User denied the required permission. |
| `2001` | `ResultCode.PAYMENT_FAILED` | Payment failed. |

> **Note**: The `onFailure` callback is invoked with these predefined codes. Defining custom error codes is not supported.