Ok. In your web service, define your class. Then accept the type of Fax in your sendInformation method of the WS. Now, when you consume the web service, a type of Fax will become available. Visual studio creates code files to represent the objects you can pass up so, without you physically defining the file locally, you can;
Fax createFile = new Fax( );
createFile.Reference = txtReference.Text;
createFile.AccountNo = txtAccountNo.Text;
InfoService info = new InfoService( );
info.SendInformation( createFile );
Where your WS method looks like;
[WebMethod]
public void SendInformation( Fax info)
{
// do something with info in here
}