diff --git a/modules/EcommerceFinance/Services/SupplierReturnAccounting.php b/modules/EcommerceFinance/Services/SupplierReturnAccounting.php
index a0749be6..c58145c3 100644
--- a/modules/EcommerceFinance/Services/SupplierReturnAccounting.php
+++ b/modules/EcommerceFinance/Services/SupplierReturnAccounting.php
@@ -35,8 +35,9 @@ class SupplierReturnAccounting
         }
 
         $qty = $this->number($row['qty'] ?? 0);
-        $unitPrice = $this->number($row['unit_price'] ?? $row['guess_unit_price'] ?? 0);
-        $amount = $this->number($row['amount'] ?? $row['guess_amount'] ?? 0);
+        // 厂家净扣减只按实际单价/金额计算，不能用预估单价或预估金额兜底。
+        $unitPrice = $this->number($row['unit_price'] ?? 0);
+        $amount = $this->number($row['amount'] ?? 0);
         if ($amount === 0.0 && $qty !== 0.0) {
             $amount = $qty * $unitPrice;
         }
diff --git a/tests/Unit/EcommerceFinance/SupplierReturnAccountingTest.php b/tests/Unit/EcommerceFinance/SupplierReturnAccountingTest.php
index ff175c38..40b507d1 100644
--- a/tests/Unit/EcommerceFinance/SupplierReturnAccountingTest.php
+++ b/tests/Unit/EcommerceFinance/SupplierReturnAccountingTest.php
@@ -78,4 +78,38 @@ class SupplierReturnAccountingTest extends TestCase
         $this->assertSame(3.0, $row['_supplier_qty']);
         $this->assertSame(750.0, $row['_supplier_amount']);
     }
+
+    public function test_supplier_net_amount_never_uses_estimated_price_or_amount(): void
+    {
+        $accounting = new SupplierReturnAccounting();
+        $rows = [
+            [
+                'qty' => '2',
+                'unit_price' => '50',
+                'amount' => '100',
+                'guess_unit_price' => '999',
+                'guess_amount' => '999',
+            ],
+            [
+                'qty' => '5',
+                'unit_price' => '0',
+                'amount' => '0',
+                'guess_unit_price' => '30',
+                'guess_amount' => '150',
+            ],
+            [
+                'qty' => '3',
+                'unit_price' => '20',
+                'amount' => '0',
+                'guess_amount' => '999',
+            ],
+        ];
+
+        $unpriced = $accounting->enrich($rows[1]);
+        $summary = $accounting->summarize($rows);
+
+        $this->assertSame(0.0, $unpriced['_supplier_amount']);
+        $this->assertSame(10.0, $summary['supplier_qty']);
+        $this->assertSame(160.0, $summary['supplier_amount']);
+    }
 }