Hi, I'm writing a client that calls a number of WCF webservices (written externallyt to my company) that are very similar in structure. The design I was hoping to use is to manually build the SOAP message from XML chunks that are stored in a database and then processed through a generic web service handler class. I have access to the WSDL's for each webservice and example working XML. The design approach is such that we can easily add to the message dynamically, hence the reason for not using the auto generated proxy classes I am basically at the last part now with the entire SOAP message constructed but am getting a SOAP fault security error returned. I have used fiddler to compare the message I'm sending with one that is sent using the normal (far simpler...) WCF generated proxy classes and can't see any difference apart from the id attribute of the Usertoken element in the SOAP header. This is where my lack of experience in this area isn't helping. I think this is because the id is generated automatically (presumably because we're using https). My question is how do I generate this programatically? I have searched for hours online but the majority of solutions are either using the proxy classes or not over https. I have briefly looked at WCE but aware this is replaced by WCF now so don't want to waste time looking into this if it's not the solution. Any help with this would be greatly appreciated. I can post some code examples when I'm back in work if it will help but the method I'm using is very straightforward and only using XElements and such like at the moment (as we're using linq to sql). thanks, Andy