# Activating Expired Key
source: https://developer.mastercard.com/mastercard-developers-api/documentation/errors/activating-expired-key/index.md

This error occurs when you attempt to activate an expired key.

### Solution {#solution}

Ensure the key you are trying to activate is valid and has not expired.

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

**HTTP code 400**

```JSON
{
  "Errors": {
    "Error": [
      {
        "Source": "DEVELOPERS_API",
        "ReasonCode": "ACTIVATING_EXPIRED_KEY",
        "Description": "You cannot activate an expired key.",
        "Details": "You cannot activate an expired credential",
        "Recoverable": false
      }
    ]
  }
}
```

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