> For the complete documentation index, see [llms.txt](https://prepaidify.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://prepaidify.gitbook.io/docs/virtual-card/page-integration/explanation-of-return-codes.md).

# Explanation of Return Codes

### Return Code

You may receive the following response codes when calling the API, and you can refer to these codes:

| Code | Desc                          |
| ---- | ----------------------------- |
| 0    | Success                       |
| 1    | System Exception              |
| 1002 | Parameter Validation Error    |
| 1006 | Signature Verification Failed |