I am attempting to create a wcf service that accepts any input (Action="*") and then deserialize the message after determining its type. For the purposes of testing deserialization I am currently hard-coding the type for the test service. I get no errors from the deserialization process, but only the outer object is populated after deserialization occurs. All inner fields are null. I can process the same request against the original wcf service successfully. I am deserializing this way, where knownTypes is a type list of expected types: DataContractSerializer ser = new DataContractSerializer(new createEligibilityRuleSet ().GetType(), knownTypes); createEligibilityRuleSet newReq = buf.CreateMessage().GetBody<createEligibilityRuleSet>(ser); Here is the class and sub-classes of the request object. These classes are generated by svcutil using a top down approach from an existing wsdl. I have tried replacing the XmlTypeAttributes with DataContracts and the XmlElements with DataMembers with no difference. It is the instance of CreateEligibilityRuleSetSvcRequest on the createEligibilityRuleSet object that is null. I have included the request retrieved from the request at the bottom /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("svcutil", "3.0.4506.2152")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true, Namespace = "http://RulesEngineServicesLibrary/RulesEngineServices")] public partial class createEligibilityRuleSet { private CreateEligibilityRuleSetSvcRequest requestField; /// <remarks/> [System.Xml.Serialization.XmlElementAttribute(Form = System.Xml.Schema.XmlSchemaForm.Unqualified, IsNullable = true, Order = 0)] public CreateEligibilityRuleSetSvcRequest request { get { return this.requestField; } set { this.requestField = value; } } } /// <remarks/> [System.CodeDom.Compiler.GeneratedCodeAttribute("svcutil", "3.0.4506.2152")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(Namespace = "http://RulesEngineServicesLibrary")] public partial class CreateEligibilityRuleSetSvcRequest : RulesEngineServicesSvcRequest { private string requestField; /// <remarks/> [System.Xml.Serialization.XmlElementAttribute(Form = System.Xml.Schema.XmlSchemaForm.Unqualified, Order = 0)] public string request { get { return this.requestField; } set { this.requestField = value; } } } [System.Xml.Serialization.XmlIncludeAttribute(typeof(CreateEligibilityRuleSetSvcRequest))] [System.Xml.Serialization.XmlIncludeAttribute(typeof(ApplyMemberEligibilitySvcRequest))] [System.Xml.Serialization.XmlIncludeAttribute(typeof(CreateCompletionCriteriaRuleSetSvcRequest))] [System.Xml.Serialization.XmlIncludeAttribute(typeof(CopyRuleSetSvcRequest))] [System.Xml.Serialization.XmlIncludeAttribute(typeof(DeleteRuleSetByIDSvcRequest))] [System.CodeDom.Compiler.GeneratedCodeAttribute("svcutil", "3.0.4506.2152")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(Namespace = "http://RulesEngineServicesLibrary")] public partial class RulesEngineServicesSvcRequest : ServiceRequest { } /// <remarks/> [System.Xml.Serialization.XmlIncludeAttribute(typeof(RulesEngineServicesSvcRequest))] [System.Xml.Serialization.XmlIncludeAttribute(typeof(CreateEligibilityRuleSetSvcRequest))] [System.Xml.Serialization.XmlIncludeAttribute(typeof(ApplyMemberEligibilitySvcRequest))] [System.Xml.Serialization.XmlIncludeAttribute(typeof(CreateCompletionCriteriaRuleSetSvcRequest))] [System.Xml.Serialization.XmlIncludeAttribute(typeof(CopyRuleSetSvcRequest))] [System.Xml.Serialization.XmlIncludeAttribute(typeof(DeleteRuleSetByIDSvcRequest))] [System.CodeDom.Compiler.GeneratedCodeAttribute("svcutil", "3.0.4506.2152")] [System.SerializableAttribute()] [System.Diagnostics.DebuggerStepThroughAttribute()] [System.ComponentModel.DesignerCategoryAttribute("code")] [System.Xml.Serialization.XmlTypeAttribute(Namespace = "http://FELibrary")] public partial class ServiceRequest { private string applicationIdField; /// <remarks/> [System.Xml.Serialization.XmlElementAttribute(Form = System.Xml.Schema.XmlSchemaForm.Unqualified, Order = 0)] public string applicationId { get { return this.applicationIdField; } set { this.applicationIdField = value; } } } Request from client comes on Message body as below. Retrieved from Message at runtime. <soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:rul="http://RulesEngineServicesLibrary/RulesEngineServices"> <soap:Header/> <soap:Body> <rul:createEligibilityRuleSet> <request> <applicationId>test</applicationId> <request>Perf Rule Set1</request> </request> </rul:createEligibilityRuleSet> </soap:Body> </soap:Envelope>