{
  "error": {
    "code": 409,
    "documentation_url": "https://developer.gocardless.com/pro#idempotent_creation_conflict",
    "errors": [
      {
        "message": "A resource has already been created with this idempotency key",
        "reason": "idempotent_creation_conflict",
        "links": {
          "conflicting_resource_id": "ID123"
        }
      }
    ],
    "message": "A resource has already been created with this idempotency key",
    "request_id": "9aac0445-fd1e-4dc2-8854-a5a6afbaaeae",
    "type": "invalid_state"
  }
}