Errors in SOAP should be returned as SOAP Faults. A SOAP Fault contains specific information detailing the reason for the Fault. PEAR::SOAP provides a SOAP_Fault class to aid in returning faults. Faults can be of four basic types: VersionMismatch, MustUnderstand, Client and Server: VersionMismatch: invalid namespace for the SOAP Envelope MustUnderstand: a required header was not understood by the server Client: the message sent by the client was not properly formed, or did not contain the necessary information to fulfill the request. Server: the message could not be processed Faults can also contain other information, such as a basic message describing the fault, the URI of the originator of the fault, and a detail field that can be used to provide additional information on the fault. SOAP-ENV:Client You sent an empty string urn:SOAP_Example_Server ]]> method_namespace; $detail = NULL; return new SOAP_Fault($faultstring, $faultcode, $faultactor, $detail); } return $inputString; } } $soapclass = new SOAP_Example_Server(); $server->addObjectMap($soapclass); $server->service($HTTP_RAW_POST_DATA); ?>]]> call('echoStringSimple', array('inputString' => NULL), array('namespace' => 'urn:SOAP_Example_Server'); if (PEAR::isError($result)) { // handle the error condition echo $result->getMessage(); } ?>]]>