diff --git a/app/Http/Requests/Admin/Manage/TransactionRequest.php b/app/Http/Requests/Admin/Manage/TransactionRequest.php
index 86b33b1..ad3b924 100644
--- a/app/Http/Requests/Admin/Manage/TransactionRequest.php
+++ b/app/Http/Requests/Admin/Manage/TransactionRequest.php
@@ -35,7 +35,7 @@ public function rules(): array
             'customer_id' => ['nullable', 'integer', Rule::exists('customers', 'id')],
             'marketing_id' => ['nullable', 'integer', Rule::exists('users', 'id')],
             'discount' => ['nullable', 'integer', 'min:0'],
-            'nego_price' => ['nullable', 'integer'],
+            'nego_price' => ['nullable', 'integer', 'min:0'],
             'is_completed' => ['sometimes', 'boolean'],
             'tiktok_order_id' => ['nullable', 'string', 'max:100'],
             'shopee_order_id' => ['nullable', 'string', 'max:100'],
diff --git a/app/Services/Admin/Manage/TransactionService.php b/app/Services/Admin/Manage/TransactionService.php
index 31b5bff..cfc5a43 100644
--- a/app/Services/Admin/Manage/TransactionService.php
+++ b/app/Services/Admin/Manage/TransactionService.php
@@ -210,8 +210,10 @@ public function store(array $data): Order
             $itemRows = $this->buildItemRows($data['items'], $stockType, $priceType, $now, $subtotal, $totalCost);
 
             $discount = (int) ($data['discount'] ?? 0);
-            $negoPrice = ! empty($data['nego_price']) ? (int) $data['nego_price'] : null;
-            $totalAmount = $subtotal - $discount - ($negoPrice ?? 0);
+            $priceBeforeNego = $subtotal - $discount;
+            $negoFinalPrice = ! empty($data['nego_price']) ? (int) $data['nego_price'] : null;
+            $totalAmount = $negoFinalPrice ?? $priceBeforeNego;
+            $negoPrice = $negoFinalPrice !== null ? $priceBeforeNego - $negoFinalPrice : null;
 
             if ($totalAmount <= 0) {
                 throw ValidationException::withMessages([
@@ -219,6 +221,12 @@ public function store(array $data): Order
                 ]);
             }
 
+            if ($negoPrice !== null && $negoPrice < 0) {
+                throw ValidationException::withMessages([
+                    'nego_price' => 'Harga nego tidak boleh lebih besar dari harga sebelum nego.',
+                ]);
+            }
+
             $order = Order::create([
                 'created_by_id' => auth()->id(),
                 'customer_id' => $data['customer_id'] ?? null,
@@ -294,8 +302,10 @@ public function update(Order $order, array $data): Order
             $itemRows = $this->buildItemRows($data['items'], $stockType, $priceType, $now, $subtotal, $totalCost);
 
             $discount = (int) ($data['discount'] ?? 0);
-            $negoPrice = ! empty($data['nego_price']) ? (int) $data['nego_price'] : null;
-            $totalAmount = $subtotal - $discount - ($negoPrice ?? 0);
+            $priceBeforeNego = $subtotal - $discount;
+            $negoFinalPrice = ! empty($data['nego_price']) ? (int) $data['nego_price'] : null;
+            $totalAmount = $negoFinalPrice ?? $priceBeforeNego;
+            $negoPrice = $negoFinalPrice !== null ? $priceBeforeNego - $negoFinalPrice : null;
 
             if ($totalAmount <= 0) {
                 throw ValidationException::withMessages([
@@ -303,6 +313,12 @@ public function update(Order $order, array $data): Order
                 ]);
             }
 
+            if ($negoPrice !== null && $negoPrice < 0) {
+                throw ValidationException::withMessages([
+                    'nego_price' => 'Harga nego tidak boleh lebih besar dari harga sebelum nego.',
+                ]);
+            }
+
             foreach ($itemRows as &$row) {
                 $row['order_id'] = $order->id;
             }
diff --git a/resources/js/pages/admin/manage/transaction/create.tsx b/resources/js/pages/admin/manage/transaction/create.tsx
index f8a2c22..f80c56f 100644
--- a/resources/js/pages/admin/manage/transaction/create.tsx
+++ b/resources/js/pages/admin/manage/transaction/create.tsx
@@ -291,7 +291,7 @@ export default function TransactionCreate({
         0,
     );
 
-    const total = subtotal - discount - (negoPrice ?? 0);
+    const total = negoPrice ?? (subtotal - discount);
 
     const updateQuantity = useCallback((variantId: number, value: number) => {
         setQuantities((prev) => ({
@@ -980,7 +980,7 @@ export default function TransactionCreate({
                                                     placeholder="0"
                                                 />
                                                 <FieldDescription>
-                                                    Jumlah potongan harga yang dinego customer.
+                                                    Harga akhir setelah dinego dengan customer.
                                                 </FieldDescription>
                                                 <InputError
                                                     message={errors.nego_price}
diff --git a/resources/js/pages/admin/manage/transaction/edit.tsx b/resources/js/pages/admin/manage/transaction/edit.tsx
index e12b328..e5805ed 100644
--- a/resources/js/pages/admin/manage/transaction/edit.tsx
+++ b/resources/js/pages/admin/manage/transaction/edit.tsx
@@ -92,7 +92,15 @@ export default function TransactionEdit({
     const [customerId, setCustomerId] = useState<number | null>(transaction.customer_id);
     const [marketingId, setMarketingId] = useState<number | null>(transaction.marketing_id);
     const [discount, setDiscount] = useState(transaction.discount);
-    const [negoPrice, setNegoPrice] = useState<number | null>(transaction.nego_price);
+    const initialSubtotal = (transaction.items ?? []).reduce(
+        (sum, item) => sum + item.unit_price * item.quantity,
+        0,
+    );
+    const [negoPrice, setNegoPrice] = useState<number | null>(
+        transaction.nego_price != null
+            ? initialSubtotal - transaction.discount - transaction.nego_price
+            : null,
+    );
     const [isCompleted, setIsCompleted] = useState(transaction.is_completed);
     const [notes, setNotes] = useState(transaction.notes ?? '');
     const [photo, setPhoto] = useState<string | null>(transaction.photo_key);
@@ -268,7 +276,7 @@ export default function TransactionEdit({
         0,
     );
 
-    const total = subtotal - discount - (negoPrice ?? 0);
+    const total = negoPrice ?? (subtotal - discount);
 
     const updateQuantity = useCallback((variantId: number, value: number) => {
         setQuantities((prev) => ({
@@ -889,7 +897,7 @@ export default function TransactionEdit({
                                                     placeholder="0"
                                                 />
                                                 <FieldDescription>
-                                                    Jumlah potongan harga yang dinego customer.
+                                                    Harga akhir setelah dinego dengan customer.
                                                 </FieldDescription>
                                                 <InputError
                                                     message={errors.nego_price}