CODE - UC SEG STATUS NOT ALLOWED-0003 when requesting EnhancedAirBookRQ

I have to check your code, One thing is that if you getting your result from postman .. Then there is a good option for getting curl code from the postman. By click on code > change HTTP option to PHP curl >copy to clipboard . If you try with this way of write code, you have to change little changes.

And one more thing, A very good answer have given here UC status . UC status related to UN-CONFIRMED status. Please have a look here. Thanks

This is an example , for how to pass your post field data in xml form :

 $curl = curl_init();    curl_setopt_array($curl, array(      CURLOPT_PORT => "",      CURLOPT_URL => "url here",      CURLOPT_RETURNTRANSFER => true,      CURLOPT_ENCODING => "",      CURLOPT_MAXREDIRS => 10,      CURLOPT_TIMEOUT => 30,      CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,      CURLOPT_CUSTOMREQUEST => "POST",      CURLOPT_POSTFIELDS => "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<soap:Envelope xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\">\n  <soap:Body> soap body part </soap:Body>\n</soap:Envelope>",      CURLOPT_HTTPHEADER => array(        "cache-control: no-cache",        "content-type: text/xml"      ),    ));    $response = curl_exec($curl);    $err = curl_error($curl);    curl_close($curl);    if ($err) {      echo "cURL Error #:" . $err;    } else {      echo $response;    }

I have tried you code and modified some part of it. please try using below code

        <?php    header('Content-Type: application/xml');    $xmldata='<?xml version="1.0" encoding="utf-8"?>    <soap-env:Envelope xmlns:soap-env="http://schemas.xmlsoap.org/soap/envelope/">    <soap-env:Header>    <eb:MessageHeader xmlns:eb="http://www.ebxml.org/namespaces/messageHeader">    <eb:From>    <eb:PartyId eb:type="urn:x12.org.IO5:01">info@gandakiintl.com</eb:PartyId>    </eb:From>    <eb:To>    <eb:PartyId eb:type="urn:x12.org.IO5:01">webservices.sabre.com</eb:PartyId>    </eb:To>    <eb:ConversationId>111@gandakiintl.com</eb:ConversationId>    <eb:Service eb:type="SabreXML">Enhanced Air Book Request</eb:Service>    <eb:Action>EnhancedAirBookRQ</eb:Action>    <eb:CPAID>T198</eb:CPAID>    <eb:MessageData>    <eb:MessageId>mid:11110info@gandakiintl.com</eb:MessageId>    <eb:Timestamp>2016-10-17T05-27-10Z</eb:Timestamp>    <eb:TimeToLive>2016-10-17T05-27-10Z</eb:TimeToLive>    </eb:MessageData>    </eb:MessageHeader>    <wsse:Security xmlns:wsse="http://schemas.xmlsoap.org/ws/2002/12/secext">    <wsse:BinarySecurityToken>Shared/IDL:IceSess\/SessMgr:1\.0.IDL/Common/!ICESMS\/ACPCRTD!ICESMSLB\/CRT.LB!-3322625022286234335!532307!0</wsse:BinarySecurityToken>    </wsse:Security>    </soap-env:Header>    <soap-env:Body>    <EnhancedAirBookRQ xmlns="http://services.sabre.com/sp/eab/v3_6" version="3.6.0" HaltOnError="true">    <OTA_AirBookRQ>    <HaltOnStatus Code="UC"/>    <HaltOnStatus Code="LL"/>    <HaltOnStatus Code="UL"/>    <HaltOnStatus Code="UN"/>    <HaltOnStatus Code="NO"/>    <HaltOnStatus Code="HL"/>    <OriginDestinationInformation>    <FlightSegment NumberInParty="1" Status="NN" FlightNumber="281" ResBookDesigCode="W" DepartureDateTime="2017-04-13T13:10:00" ArrivalDateTime="2017-04-13T14:40:00">    <DestinationLocation LocationCode="DEL"/>    <Equipment AirEquipType="73H"/>    <MarketingAirline FlightNumber="281" Code="9W"/>    <OriginLocation LocationCode="KTM"/>    </FlightSegment>    </OriginDestinationInformation>    </OTA_AirBookRQ>    <OTA_AirPriceRQ>    <PriceRequestInformation Retain="true">    <OptionalQualifiers>    <FlightQualifiers>    <VendorPrefs>    <Airline Code="9W"/>    </VendorPrefs>    </FlightQualifiers>    <PricingQualifiers CurrencyCode="NPR">    <PassengerType Code="ADT" Force="true" Quantity="1"/>    <Taxes>    <TaxExempt Code="NQ"/>    </Taxes>    </PricingQualifiers>    </OptionalQualifiers>    </PriceRequestInformation>    </OTA_AirPriceRQ>    <PostProcessing IgnoreAfter="false">    <RedisplayReservation/>    </PostProcessing>    <PreProcessing IgnoreBefore="false">            </PreProcessing>    </EnhancedAirBookRQ>    </soap-env:Body>    </soap-env:Envelope>';    error_reporting(E_ALL);    $wsdl = 'https://sws3-crt.cert.sabre.com';    $header = array(        "Content-type: text/xml;charset=\"utf-8\"",        "Accept: text/xml",        "Cache-Control: no-cache",        "Pragma: no-cache",        "SOAPAction: \"\"",        "Content-length: " . strlen($xmldata),    );        $ch = curl_init();              curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);        curl_setopt($ch, CURLOPT_URL, $wsdl);        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);        curl_setopt($ch, CURLOPT_TIMEOUT, 10);        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);        curl_setopt($ch, CURLOPT_POST, true);        curl_setopt($ch, CURLOPT_ENCODING, '');        curl_setopt($ch, CURLOPT_POSTFIELDS, $xmldata); // the SOAP request        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);             $response = curl_exec($ch);        $err = curl_error($ch);       print_r($response);       print_r($err);    ?>

UC status means that the itinerary you booked is not available. It could be due to a number of different things like date, class of service, etc.

Where did you get the itinerary information from? If you're using a shopping service, I'd advise you to run it again and see if the same itinerary is still returned, or if the class of service changed.