diff --git a/src/components/admin/ActivityTypeManager.tsx b/src/components/admin/ActivityTypeManager.tsx
index 85761f8..ca71f29 100644
--- a/src/components/admin/ActivityTypeManager.tsx
+++ b/src/components/admin/ActivityTypeManager.tsx
@@ -48,7 +48,8 @@ export function ActivityTypeManager() {
     title: '',
     itemCode: '',
     taxationType: '',
-    sapRefNo: ''
+    sapRefNo: '',
+    creditPostingOn: ''
   });
 
   useEffect(() => {
@@ -75,7 +76,8 @@ export function ActivityTypeManager() {
       title: '',
       itemCode: '',
       taxationType: '',
-      sapRefNo: ''
+      sapRefNo: '',
+      creditPostingOn: ''
     });
     setEditingActivityType(null);
     setShowAddDialog(true);
@@ -86,7 +88,8 @@ export function ActivityTypeManager() {
       title: activityType.title,
       itemCode: activityType.itemCode || '',
       taxationType: activityType.taxationType || '',
-      sapRefNo: activityType.sapRefNo || ''
+      sapRefNo: activityType.sapRefNo || '',
+      creditPostingOn: activityType.creditPostingOn || ''
     });
     setEditingActivityType(activityType);
     setShowAddDialog(true);
@@ -96,8 +99,8 @@ export function ActivityTypeManager() {
     try {
       setError(null);
 
-      if (!formData.title.trim() || !formData.taxationType.trim() || !formData.sapRefNo.trim()) {
-        setError('Title, Taxation Type, and Claim Document Type (SAP Ref) are required');
+      if (!formData.title.trim() || !formData.taxationType.trim() || !formData.sapRefNo.trim() || !formData.creditPostingOn.trim()) {
+        setError('Title, Taxation Type, Credit Posting On, and Claim Document Type (SAP Ref) are required');
         toast.error('Please fill in all mandatory fields');
         return;
       }
@@ -106,7 +109,8 @@ export function ActivityTypeManager() {
         title: formData.title.trim(),
         itemCode: formData.itemCode.trim() || null,
         taxationType: formData.taxationType.trim(),
-        sapRefNo: formData.sapRefNo.trim()
+        sapRefNo: formData.sapRefNo.trim(),
+        creditPostingOn: formData.creditPostingOn.trim()
       };
 
       if (editingActivityType) {
@@ -270,7 +274,10 @@ export function ActivityTypeManager() {
                       {activityType.sapRefNo && (
                         <span className="font-medium">SAP Ref: <span className="text-slate-900">{activityType.sapRefNo}</span></span>
                       )}
-                      {!activityType.itemCode && !activityType.taxationType && !activityType.sapRefNo && (
+                      {activityType.creditPostingOn && (
+                        <span className="font-medium">Credit Posting On: <Badge variant="secondary" className="ml-1 bg-slate-200 text-slate-800">{activityType.creditPostingOn}</Badge></span>
+                      )}
+                      {!activityType.itemCode && !activityType.taxationType && !activityType.sapRefNo && !activityType.creditPostingOn && (
                         <span className="text-slate-500 italic">No additional details</span>
                       )}
                     </div>
@@ -433,6 +440,28 @@ export function ActivityTypeManager() {
               />
               <p className="text-xs text-slate-500">Required SAP reference number for CSV generation</p>
             </div>
+
+            {/* Credit Posting On Field */}
+            <div className="space-y-2">
+              <Label htmlFor="creditPostingOn" className="text-sm font-semibold text-slate-900 flex items-center gap-1">
+                Credit Posting On <span className="text-red-500">*</span>
+              </Label>
+              <Select
+                value={formData.creditPostingOn}
+                onValueChange={(value) => setFormData({ ...formData, creditPostingOn: value })}
+              >
+                <SelectTrigger id="creditPostingOn" className="h-11 border-slate-300 focus:border-re-green focus:ring-2 focus:ring-re-green/20 rounded-lg transition-all shadow-sm">
+                  <SelectValue placeholder="Select Credit Posting Group" />
+                </SelectTrigger>
+                <SelectContent className="rounded-lg">
+                  <SelectItem value="Vehicle" className="p-3">Vehicle</SelectItem>
+                  <SelectItem value="Spares" className="p-3">Spares</SelectItem>
+                  <SelectItem value="GMA" className="p-3">GMA</SelectItem>
+                  <SelectItem value="Apparel" className="p-3">Apparel</SelectItem>
+                </SelectContent>
+              </Select>
+              <p className="text-xs text-slate-500">Categorize for dealer validation (Vehicle, Spares, GMA, or Apparel)</p>
+            </div>
           </div>
 
           <DialogFooter className="gap-3 pt-4 border-t border-slate-100 px-6 pb-6 flex-shrink-0">
@@ -445,7 +474,7 @@ export function ActivityTypeManager() {
             </Button>
             <Button
               onClick={handleSave}
-              disabled={!formData.title.trim() || !formData.taxationType || !formData.sapRefNo.trim()}
+              disabled={!formData.title.trim() || !formData.taxationType || !formData.sapRefNo.trim() || !formData.creditPostingOn}
               className="h-11 bg-re-green hover:bg-re-green/90 text-white shadow-md hover:shadow-lg transition-all disabled:opacity-50 disabled:cursor-not-allowed"
             >
               <FileText className="w-4 h-4 mr-2" />
diff --git a/src/dealer-claim/components/request-creation/ClaimManagementWizard.tsx b/src/dealer-claim/components/request-creation/ClaimManagementWizard.tsx
index a8bea62..fbe7164 100644
--- a/src/dealer-claim/components/request-creation/ClaimManagementWizard.tsx
+++ b/src/dealer-claim/components/request-creation/ClaimManagementWizard.tsx
@@ -149,6 +149,7 @@ export function ClaimManagementWizard({ onBack, onSubmit }: ClaimManagementWizar
     dealerEmail: '',
     dealerPhone: '',
     dealerAddress: '',
+    dealerItemGroup: '', // For validation
     activityDate: undefined as Date | undefined,
     location: '',
     requestDescription: '',
@@ -227,25 +228,57 @@ export function ClaimManagementWizard({ onBack, onSubmit }: ClaimManagementWizar
 
       // Validate period dates
       if (field === 'periodStartDate') {
-        // If start date is selected and end date exists, validate end date
         if (value && updated.periodEndDate && value > updated.periodEndDate) {
-          // Clear end date if it's before the new start date
           updated.periodEndDate = undefined;
           toast.error('End date must be on or after the start date. End date has been cleared.');
         }
       } else if (field === 'periodEndDate') {
-        // If end date is selected and start date exists, validate end date
         if (value && updated.periodStartDate && value < updated.periodStartDate) {
           toast.error('End date must be on or after the start date.');
-          // Don't update the end date if it's invalid
           return prev;
         }
       }
 
+      // 1b. Validate Activity Type change against already selected Dealer
+      if (field === 'activityType' && updated.dealerCode) {
+        const selectedActivity = activityTypes.find(t => t.title === value);
+        if (selectedActivity) {
+          if (selectedActivity.creditPostingOn) {
+            const activityCategory = selectedActivity.creditPostingOn.toLowerCase();
+            const dealerGroup = (updated.dealerItemGroup || '').toLowerCase();
+
+            // If we have a dealer group, validate it
+            if (dealerGroup) {
+              let isMatch = false;
+              if (activityCategory === 'vehicle' && dealerGroup === 'vehicle') isMatch = true;
+              else if (activityCategory === 'spares' && dealerGroup === 'spares') isMatch = true;
+              else if (activityCategory === 'gma' && dealerGroup === 'gma') isMatch = true;
+              else if (activityCategory === 'apparel' && dealerGroup === 'apparel') isMatch = true;
+              else if (activityCategory === dealerGroup) isMatch = true;
+
+              if (!isMatch) {
+                toast.error(`incorrect Delercode for selected service group`, {
+                  description: `Activity requires ${selectedActivity.creditPostingOn}, but already selected dealer is ${updated.dealerItemGroup}`,
+                  duration: 6000
+                });
+                return prev;
+              }
+            }
+          } else {
+            console.warn(`[ClaimWizard] Activity type "${value}" is missing creditPostingOn configuration.`);
+          }
+        }
+      }
+
       return updated;
     });
   };
 
+  // Helper to update multiple fields at once
+  const updateMultipleFormData = (updates: Record<string, any>) => {
+    setFormData(prev => ({ ...prev, ...updates }));
+  };
+
   const isStepValid = () => {
     switch (currentStep) {
       case 1:
@@ -331,12 +364,58 @@ export function ClaimManagementWizard({ onBack, onSubmit }: ClaimManagementWizar
         return;
       }
 
-      // Dealer is logged in, update form data
-      updateFormData('dealerCode', verifiedDealer.dealerCode);
-      updateFormData('dealerName', verifiedDealer.dealerName || verifiedDealer.displayName);
-      updateFormData('dealerEmail', verifiedDealer.email || '');
-      updateFormData('dealerPhone', verifiedDealer.phone || '');
-      updateFormData('dealerAddress', ''); // Address not available in API response
+      // 1a. Validate Category Match (Frontend UX)
+      if (formData.activityType) {
+        const selectedActivity = activityTypes.find(t => t.title === formData.activityType);
+        if (selectedActivity && selectedActivity.creditPostingOn) {
+          const activityCategory = selectedActivity.creditPostingOn.toLowerCase();
+          const dealerGroup = (verifiedDealer.itemGroup || '').toLowerCase();
+
+          let isMatch = false;
+          // Vehicle matches Vehicle
+          if (activityCategory === 'vehicle' && dealerGroup === 'vehicle') {
+            isMatch = true;
+          }
+          // Spares matches Spares (Strict)
+          else if (activityCategory === 'spares' && dealerGroup === 'spares') {
+            isMatch = true;
+          }
+          // GMA matches GMA (Strict)
+          else if (activityCategory === 'gma' && dealerGroup === 'gma') {
+            isMatch = true;
+          }
+          // Apparel matches Apparel (Strict)
+          else if (activityCategory === 'apparel' && dealerGroup === 'apparel') {
+            isMatch = true;
+          }
+          // Direct match fallback
+          else if (activityCategory === dealerGroup) {
+            isMatch = true;
+          }
+
+          if (!isMatch) {
+            toast.error(`incorrect Delercode for selected service group`, {
+              description: `Activity requires ${selectedActivity.creditPostingOn}, but dealer is ${verifiedDealer.itemGroup || 'N/A'}`,
+              duration: 6000
+            });
+            // Clear the selection
+            setDealerSearchInput('');
+            setDealerSearchResults([]);
+            setVerifyingDealer(false);
+            return;
+          }
+        }
+      }
+
+      // Dealer is logged in, update form data in one batch
+      updateMultipleFormData({
+        dealerCode: verifiedDealer.dealerCode,
+        dealerName: verifiedDealer.dealerName || verifiedDealer.displayName,
+        dealerEmail: verifiedDealer.email || '',
+        dealerPhone: verifiedDealer.phone || '',
+        dealerAddress: '',
+        dealerItemGroup: verifiedDealer.itemGroup || ''
+      });
 
       // Clear search input and results
       setDealerSearchInput(verifiedDealer.dealerName || verifiedDealer.displayName);
diff --git a/src/services/adminApi.ts b/src/services/adminApi.ts
index 69f33cb..b327a6f 100644
--- a/src/services/adminApi.ts
+++ b/src/services/adminApi.ts
@@ -44,6 +44,7 @@ export interface ActivityType {
   itemCode?: string | null;
   taxationType?: string | null;
   sapRefNo?: string | null;
+  creditPostingOn?: string | null;
   isActive?: boolean;
 }
 
diff --git a/src/services/dealerApi.ts b/src/services/dealerApi.ts
index fdf0a6c..3315540 100644
--- a/src/services/dealerApi.ts
+++ b/src/services/dealerApi.ts
@@ -26,6 +26,7 @@ export interface DealerInfo {
   city?: string | null;
   dealerPrincipalName?: string | null;
   dealerPrincipalEmailId?: string | null;
+  itemGroup?: string | null;
 }
 
 /**