diff --git a/src/dealer-claim/components/request-detail/WorkflowTab.tsx b/src/dealer-claim/components/request-detail/WorkflowTab.tsx
index df7fe09..7042024 100644
--- a/src/dealer-claim/components/request-detail/WorkflowTab.tsx
+++ b/src/dealer-claim/components/request-detail/WorkflowTab.tsx
@@ -10,7 +10,7 @@ import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/com
 import { Badge } from '@/components/ui/badge';
 import { Button } from '@/components/ui/button';
 import { Progress } from '@/components/ui/progress';
-import { TrendingUp, Clock, CheckCircle, CircleCheckBig, Upload, Mail, Download, Receipt, Activity, AlertTriangle, AlertOctagon, XCircle, History, ChevronDown, ChevronUp, RefreshCw, RotateCw, Eye, FileSpreadsheet } from 'lucide-react';
+import { TrendingUp, Clock, CheckCircle, CircleCheckBig, Upload, Mail, Download, Receipt, Activity, AlertTriangle, AlertOctagon, XCircle, History, ChevronDown, ChevronUp, RefreshCw, RotateCw, Eye, FileSpreadsheet, X, Loader2 } from 'lucide-react';
 import { formatDateTime, formatDateDDMMYYYY } from '@/utils/dateFormatter';
 import { formatHoursMinutes } from '@/utils/slaTracker';
 import {
@@ -189,6 +189,9 @@ export function DealerClaimWorkflowTab({
   const [showHistory, setShowHistory] = useState(false);
   const [expandedVersionSteps, setExpandedVersionSteps] = useState<Set<number>>(new Set());
   const [viewSnapshot, setViewSnapshot] = useState<{ data: any, type: 'PROPOSAL' | 'COMPLETION', title?: string } | null>(null);
+  const [invoicePdfUrl, setInvoicePdfUrl] = useState<string | null>(null);
+  const [showInvoicePdfModal, setShowInvoicePdfModal] = useState(false);
+  const [invoicePdfLoading, setInvoicePdfLoading] = useState(false);
 
   // Load approval flows from real API
   const [approvalFlow, setApprovalFlow] = useState<any[]>([]);
@@ -1238,7 +1241,14 @@ export function DealerClaimWorkflowTab({
       handleRefresh();
     } catch (error: any) {
       console.error('[DealerClaimWorkflowTab] Error generating e-invoice:', error);
-      const errorMessage = error?.response?.data?.message || error?.message || 'Failed to generate e-invoice. Please try again.';
+      // Backend now translates PWC error codes to user-friendly messages in 'message' field
+      // Prefer 'message' (user-friendly) over 'error' (raw technical details)
+      const responseMessage = error?.response?.data?.message;
+      let errorMessage = responseMessage || error?.message || 'E-Invoice generation failed. Please try again.';
+      // Truncate very long error messages for toast display (keep first 300 chars)
+      if (errorMessage.length > 300) {
+        errorMessage = errorMessage.substring(0, 300) + '...';
+      }
       toast.error(errorMessage);
       throw error;
     }
@@ -1502,14 +1512,56 @@ export function DealerClaimWorkflowTab({
         return;
       }
 
-      const token = TokenManager.getAccessToken();
-      // Construct API URL for PDF preview
-      const previewUrl = `${import.meta.env.VITE_API_BASE_URL || 'http://localhost:5000/api/v1'}/dealer-claims/${requestId}/e-invoice/pdf?token=${token}`;
+      setInvoicePdfLoading(true);
+      setShowInvoicePdfModal(true);
 
-      window.open(previewUrl, '_blank');
+      // Fetch PDF securely via Authorization header (not in URL query)
+      const baseUrl = import.meta.env.VITE_API_BASE_URL || 'http://localhost:5000/api/v1';
+      const response = await fetch(`${baseUrl}/dealer-claims/${requestId}/e-invoice/pdf`, {
+        headers: {
+          'Authorization': `Bearer ${TokenManager.getAccessToken()}`
+        }
+      });
+
+      if (!response.ok) {
+        throw new Error('Failed to fetch invoice PDF');
+      }
+
+      const blob = await response.blob();
+      const blobUrl = window.URL.createObjectURL(blob);
+
+      // Revoke previous blob URL to prevent memory leaks
+      if (invoicePdfUrl) {
+        window.URL.revokeObjectURL(invoicePdfUrl);
+      }
+
+      setInvoicePdfUrl(blobUrl);
     } catch (error) {
       console.error('Failed to preview invoice:', error);
-      toast.error('Failed to open invoice preview');
+      toast.error('Failed to load invoice preview');
+      setShowInvoicePdfModal(false);
+    } finally {
+      setInvoicePdfLoading(false);
+    }
+  };
+
+  const handleCloseInvoicePdf = () => {
+    setShowInvoicePdfModal(false);
+    if (invoicePdfUrl) {
+      window.URL.revokeObjectURL(invoicePdfUrl);
+      setInvoicePdfUrl(null);
+    }
+  };
+
+  const handleDownloadInvoicePdf = () => {
+    if (invoicePdfUrl) {
+      const a = document.createElement('a');
+      a.href = invoicePdfUrl;
+      a.download = `Invoice_${request.requestNumber || 'Download'}.pdf`;
+      document.body.appendChild(a);
+      a.click();
+      document.body.removeChild(a);
+      toast.success('Invoice PDF downloaded');
     }
   };
 
@@ -2435,6 +2487,7 @@ export function DealerClaimWorkflowTab({
         requestId={request?.id || request?.requestId}
         previousProposalData={versionHistory?.find(v => v.snapshotType === 'PROPOSAL')?.snapshotData}
         documentPolicy={documentPolicy}
+        taxationType={request?.claimDetails?.taxationType}
       />
 
       {/* Initiator Proposal Approval Modal */}
@@ -2458,6 +2511,7 @@ export function DealerClaimWorkflowTab({
           // proposalSnapshots[1] is the previous proposal (last iteration - 1)
           return proposalSnapshots.length > 1 ? proposalSnapshots[1].snapshotData : null;
         })()}
+        taxationType={request?.claimDetails?.taxationType}
       />
 
       {/* Dept Lead IO Approval Modal */}
@@ -2484,6 +2538,7 @@ export function DealerClaimWorkflowTab({
         defaultGstRate={request?.claimDetails?.defaultGstRate}
         requestId={request?.id || request?.requestId}
         documentPolicy={documentPolicy}
+        taxationType={request?.claimDetails?.taxationType}
       />
 
       {/* DMS Push Modal */}
@@ -2818,6 +2873,65 @@ export function DealerClaimWorkflowTab({
         type={viewSnapshot?.type || 'PROPOSAL'}
         title={viewSnapshot?.title}
       />
+
+      {/* Invoice PDF Viewer Modal */}
+      {showInvoicePdfModal && (
+        <div className="fixed inset-0 z-50 flex items-center justify-center">
+          {/* Backdrop */}
+          <div className="absolute inset-0 bg-black/60" onClick={handleCloseInvoicePdf} />
+          {/* Modal */}
+          <div className="relative w-[95vw] max-w-5xl h-[90vh] bg-white rounded-xl shadow-2xl flex flex-col overflow-hidden">
+            {/* Header */}
+            <div className="flex items-center justify-between px-5 py-3 border-b bg-gray-50">
+              <div className="flex items-center gap-2">
+                <Receipt className="w-5 h-5 text-amber-600" />
+                <h3 className="font-semibold text-gray-900">Invoice Preview</h3>
+                <Badge className="bg-amber-100 text-amber-800 text-xs">{request.requestNumber}</Badge>
+              </div>
+              <div className="flex items-center gap-2">
+                {invoicePdfUrl && (
+                  <Button
+                    variant="outline"
+                    size="sm"
+                    onClick={handleDownloadInvoicePdf}
+                    className="gap-1.5 text-xs"
+                  >
+                    <Download className="w-3.5 h-3.5" />
+                    Download
+                  </Button>
+                )}
+                <Button
+                  variant="ghost"
+                  size="icon"
+                  onClick={handleCloseInvoicePdf}
+                  className="h-8 w-8 hover:bg-gray-200"
+                >
+                  <X className="w-4 h-4" />
+                </Button>
+              </div>
+            </div>
+            {/* Body */}
+            <div className="flex-1 overflow-hidden">
+              {invoicePdfLoading ? (
+                <div className="flex flex-col items-center justify-center h-full gap-3">
+                  <Loader2 className="w-8 h-8 text-amber-600 animate-spin" />
+                  <p className="text-sm text-gray-500">Loading invoice...</p>
+                </div>
+              ) : invoicePdfUrl ? (
+                <iframe
+                  src={invoicePdfUrl}
+                  className="w-full h-full border-0"
+                  title="Invoice PDF Preview"
+                />
+              ) : (
+                <div className="flex items-center justify-center h-full">
+                  <p className="text-sm text-gray-500">Failed to load invoice</p>
+                </div>
+              )}
+            </div>
+          </div>
+        </div>
+      )}
     </>
   );
 }
diff --git a/src/dealer-claim/components/request-detail/modals/DealerCompletionDocumentsModal.tsx b/src/dealer-claim/components/request-detail/modals/DealerCompletionDocumentsModal.tsx
index 42a5ed9..ae9acd5 100644
--- a/src/dealer-claim/components/request-detail/modals/DealerCompletionDocumentsModal.tsx
+++ b/src/dealer-claim/components/request-detail/modals/DealerCompletionDocumentsModal.tsx
@@ -72,6 +72,7 @@ interface DealerCompletionDocumentsModalProps {
     maxFileSizeMB: number;
     allowedFileTypes: string[];
   };
+  taxationType?: string | null;
 }
 
 export function DealerCompletionDocumentsModal({
@@ -84,6 +85,7 @@ export function DealerCompletionDocumentsModal({
   requestId: _requestId,
   defaultGstRate = 18,
   documentPolicy,
+  taxationType,
 }: DealerCompletionDocumentsModalProps) {
   const [activityCompletionDate, setActivityCompletionDate] = useState('');
   const [numberOfParticipants, setNumberOfParticipants] = useState('');
@@ -618,6 +620,11 @@ export function DealerCompletionDocumentsModal({
               <Upload className="w-5 h-5 sm:w-6 sm:h-6 text-[--re-green]" />
               Activity Completion Documents
             </DialogTitle>
+            {taxationType && (
+              <Badge className={`mt-1 mb-1 w-fit ${taxationType === 'GST' ? 'bg-[#2d4a3e] text-white hover:bg-[#2d4a3e]/90' : 'bg-slate-200 text-slate-800 hover:bg-slate-200/90'}`}>
+                {taxationType === 'GST' ? 'GST Claim' : 'Non-GST Claim'}
+              </Badge>
+            )}
             <DialogDescription className="text-sm sm:text-base">
               Step 5: Upload completion proof and final documents
             </DialogDescription>
diff --git a/src/dealer-claim/components/request-detail/modals/DealerProposalSubmissionModal.tsx b/src/dealer-claim/components/request-detail/modals/DealerProposalSubmissionModal.tsx
index 0a61e94..e796bd3 100644
--- a/src/dealer-claim/components/request-detail/modals/DealerProposalSubmissionModal.tsx
+++ b/src/dealer-claim/components/request-detail/modals/DealerProposalSubmissionModal.tsx
@@ -72,6 +72,7 @@ interface DealerProposalSubmissionModalProps {
     maxFileSizeMB: number;
     allowedFileTypes: string[];
   };
+  taxationType?: string | null;
 }
 
 export function DealerProposalSubmissionModal({
@@ -85,6 +86,7 @@ export function DealerProposalSubmissionModal({
   previousProposalData,
   defaultGstRate = 18,
   documentPolicy,
+  taxationType,
 }: DealerProposalSubmissionModalProps) {
   const [proposalDocument, setProposalDocument] = useState<File | null>(null);
 
@@ -548,6 +550,11 @@ export function DealerProposalSubmissionModal({
             <Upload className="w-5 h-5 lg:w-6 lg:h-6 text-[--re-green]" />
             Dealer Proposal Submission
           </DialogTitle>
+          {taxationType && (
+            <Badge className={`mt-1 mb-1 w-fit ${taxationType === 'GST' ? 'bg-[#2d4a3e] text-white hover:bg-[#2d4a3e]/90' : 'bg-slate-200 text-slate-800 hover:bg-slate-200/90'}`}>
+              {taxationType === 'GST' ? 'GST Claim' : 'Non-GST Claim'}
+            </Badge>
+          )}
           <DialogDescription className="text-sm lg:text-base">
             Step 1: Upload proposal and planning details
           </DialogDescription>
diff --git a/src/dealer-claim/components/request-detail/modals/InitiatorProposalApprovalModal.tsx b/src/dealer-claim/components/request-detail/modals/InitiatorProposalApprovalModal.tsx
index 97e09d9..e9c777d 100644
--- a/src/dealer-claim/components/request-detail/modals/InitiatorProposalApprovalModal.tsx
+++ b/src/dealer-claim/components/request-detail/modals/InitiatorProposalApprovalModal.tsx
@@ -71,6 +71,7 @@ interface InitiatorProposalApprovalModalProps {
   requestId?: string;
   request?: any; // Request object to check IO blocking status
   previousProposalData?: any;
+  taxationType?: string | null;
 }
 
 export function InitiatorProposalApprovalModal({
@@ -85,6 +86,7 @@ export function InitiatorProposalApprovalModal({
   requestId: _requestId, // Prefix with _ to indicate intentionally unused
   request,
   previousProposalData,
+  taxationType,
 }: InitiatorProposalApprovalModalProps) {
   const [comments, setComments] = useState('');
   const [submitting, setSubmitting] = useState(false);
@@ -285,6 +287,11 @@ export function InitiatorProposalApprovalModal({
           <DialogDescription className="text-xs lg:text-sm">
             Step 2: Review dealer proposal and make a decision
           </DialogDescription>
+          {taxationType && (
+            <Badge className={`mt-1 mb-1 w-fit ${taxationType === 'GST' ? 'bg-[#2d4a3e] text-white hover:bg-[#2d4a3e]/90' : 'bg-slate-200 text-slate-800 hover:bg-slate-200/90'}`}>
+              {taxationType === 'GST' ? 'GST Claim' : 'Non-GST Claim'}
+            </Badge>
+          )}
           <div className="space-y-1 mt-2 text-xs text-gray-600">
             <div className="flex flex-wrap gap-x-4 gap-y-1">
               <div>
diff --git a/src/services/adminApi.ts b/src/services/adminApi.ts
index c8e4939..1863757 100644
--- a/src/services/adminApi.ts
+++ b/src/services/adminApi.ts
@@ -135,7 +135,7 @@ export const bulkImportHolidays = async (holidays: Partial<Holiday>[]): Promise<
 };
 
 /**
- * Get all activity types (public endpoint - no auth required)
+ * Get all active activity types (requires authentication)
  */
 export const getActivityTypes = async (): Promise<ActivityType[]> => {
   const response = await apiClient.get('/config/activity-types');