diff --git a/modules/helpdesk/lib/Module/Helpdesk/Service/BcSoapGateway.php b/modules/helpdesk/lib/Module/Helpdesk/Service/BcSoapGateway.php
index 6c1270d..a79602d 100644
--- a/modules/helpdesk/lib/Module/Helpdesk/Service/BcSoapGateway.php
+++ b/modules/helpdesk/lib/Module/Helpdesk/Service/BcSoapGateway.php
@@ -345,11 +345,14 @@ XML;
     {
         $escapedContactNo = htmlspecialchars($contactNo, ENT_XML1 | ENT_QUOTES, 'UTF-8');
 
+        // BC signature: GetTicketFile(TicketNo, EntryNo, ContactNo, ICISupportFilePort)
+        // The old monolith omitted ticketNo — BC resolves it from EntryNo.
         return <<<XML
 <?xml version="1.0" encoding="utf-8"?>
 <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:urn="urn:microsoft-dynamics-schemas/codeunit/ICISupportWebserviceAPI">
   <soap:Body>
     <urn:GetTicketFile>
+      <urn:ticketNo></urn:ticketNo>
       <urn:entryNo>{$entryNo}</urn:entryNo>
       <urn:contactNo>{$escapedContactNo}</urn:contactNo>
       <urn:iCISupportFilePort></urn:iCISupportFilePort>