# Sending a Request

Please note, that it is not sufficient to send an UTF-8-encoded request against the gateway but that you also need to set the correct content-type (e.g. `text/xml;charset=UTF-8`).


```
HTTP method: POST
HTTP protocol version: HTTP/1.1
Char encoding: UTF-8
```

Use the following HTTP header parameters:


```
Content-Type: text/xml; charset=UTF-8
Accept: */*
Cache-Control: no-cache
Pragma: no-cache
Connection: keep-alive
```

**Multiple requests**

To ensure consistency, **it is not allowed to**  **send multiple requests for the same** **`<transaction-id>`** **at the**  **same time**. While a request is processed, the corresponding `<transaction-id>` is locked. If the gateway receives another request for this specific `<transaction-id>`, it will be rejected with a `warning` and reason code `310` and message. This request has to be sent again after the processing of the previous request was finished.