In our android application we want certificate authentication when sending soap request. We are using ksoapLibrary-3.0.0-RC.4-jar-with-dependencies.jar library to send http/https web requests(asmx services), we have achieved the functionality to pick certificate from keystore by using one of this library method named as createSSlSocketFactoryURL() but when we call this method: httpsTransportSE.call(soapAction, envelope,headerProperty); it throws exception = "expected: START_TAG {http://schemas.xmlsoap.org/soap/envelope/}Envelope (position:START_TAG <html>@2:44 in java.io.InputStreamReader@19bb12f)". We have tried to find the solution but we cannot find the actual reason for this error. Soap envelop is correct as when we send request to another services which do not enforce certificate authentication result is retrieved with 200 status. Can anyone provide assistance regarding this issue.