I was wondering is there anyway to change the namespace prefix for the WCF SOAP request? As you can see in the example below, The Envelope has namespace "http://www.w3.org/2005/08/addressing" with prefix 'a'. I want to change this to 'foo'. How can I do that. Note I dont have control over service code I can only create proxy class from the WSDL . <s:Envelope xmlns:a="http://www.w3.org/2005/08/addressing" xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"> <s:Header> <a:Action s:mustUnderstand="1">http://www.starstandards.org/webservices/2005/10/transport/operations/MyAction</a:Action> <h:payloadManifest xmlns="http://www.starstandards.org/webservices/2005/10/transport" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:h="http://www.starstandards.org/webservices/2005/10/transport"> <manifest contentID="Content0" namespaceURI="http://www.starstandard.org/STAR/5" element="TESTMETHOD" version="5.2.4"></manifest> </h:payloadManifest> <h:Identity xmlns="urn:xxx/xxx/" xmlns:h="urn:xxx/xxx"> <SiteCode>XXXXXX</SiteCode> </h:Identity> <a:To>urn:xxx/xxx/Method1</a:To> <MessageID xmlns="http://www.w3.org/2005/08/addressing">XXXXX</MessageID> <a:ReplyTo> <a:Address>http://www.w3.org/2005/08/addressing/anonymous</a:Address> </a:ReplyTo> </s:Header> Many thanks