I managed to capture the output from my Delphi client and the way it's formed isn't correct or at least it's not the same as the output from the .net WCF Test Client. I'm not sure if this is a soap 1.1 / soap 1.2 issue. I'm using the basic http binding in the service which "should" be soap 1.1 complient. I can use IE to view the service and wsdl details and the service works fine from a .net client but Delphi is not playing ball Time for a bit more googling of binging.