# Invalid CSR
source: https://developer.mastercard.com/mastercard-developers-api/documentation/errors/invalid-csr/index.md

Invalid Certificate Signing Request (CSR).

### Solution {#solution}

Ensure your Certificate Signing Request (CSR) is valid and fulfills the requirements listed [here](https://developer.mastercard.com/platform/documentation/security-and-authentication/csr-requirements/).

### API Error Response {#api-error-response}

**HTTP code 400**

```JSON
{
  "Errors": {
    "Error": [
      {
        "Source": "DEVELOPERS_PLATFORM",
        "ReasonCode": "INVALID_CSR",
        "Description": "Invalid Certificate Signing Request (CSR)",
        "Details": "The CSR should not be blank",
        "Recoverable": false
      }
    ]
  }
}
```

[Back to Errors List](https://developer.mastercard.com/mastercard-developers-api/documentation/code-and-formats/index.md#list-of-common-api-errors)​​