diff --git a/modules/EcommerceFinance/Repositories/ThirdPartyWarehouseStorageMirrorRepository.php b/modules/EcommerceFinance/Repositories/ThirdPartyWarehouseStorageMirrorRepository.php
index db1613a5..e1686a83 100644
--- a/modules/EcommerceFinance/Repositories/ThirdPartyWarehouseStorageMirrorRepository.php
+++ b/modules/EcommerceFinance/Repositories/ThirdPartyWarehouseStorageMirrorRepository.php
@@ -60,6 +60,9 @@ class ThirdPartyWarehouseStorageMirrorRepository
 
     public const START_DATE = '2026-08-01';
 
+    /** Historical monthly report range can start one month before the flow page. */
+    private const INVENTORY_REPORT_START_DATE = '2026-07-01';
+
     /** @var array<string,string> */
     private const MOVEMENT_COLUMNS = [
         'processing_in' => '加工进仓',
@@ -299,10 +302,7 @@ class ThirdPartyWarehouseStorageMirrorRepository
         }
         $page = max($page, 1);
         $perPage = min(max($perPage, 1), 5000);
-        $period = $this->period([
-            'dimension' => 'month',
-            'period' => $filters['month'] ?? '',
-        ]);
+        $period = $this->inventoryReportPeriod((string) ($filters['month'] ?? ''));
         $authoritative = $this->monthlyInventoryAuthoritativeQuery($period, $filters);
         if ($authoritative !== null) {
             $total = $includeTotal ? (clone $authoritative)->count() : 0;
@@ -1316,6 +1316,31 @@ class ThirdPartyWarehouseStorageMirrorRepository
         ];
     }
 
+    /** @return array{dimension:string,value:string,start:string,end:string,days:int} */
+    private function inventoryReportPeriod(string $month): array
+    {
+        try {
+            $start = preg_match('/^\d{4}-\d{2}$/', trim($month)) === 1
+                ? Carbon::createFromFormat('!Y-m', trim($month))->startOfMonth()
+                : now()->startOfMonth();
+        } catch (Throwable) {
+            $start = now()->startOfMonth();
+        }
+
+        $minimum = Carbon::parse(self::INVENTORY_REPORT_START_DATE)->startOfMonth();
+        if ($start->lt($minimum)) {
+            $start = $minimum;
+        }
+
+        return [
+            'dimension' => 'month',
+            'value' => $start->format('Y-m'),
+            'start' => $start->format('Y-m-d 00:00:00'),
+            'end' => $start->copy()->addMonth()->format('Y-m-d 00:00:00'),
+            'days' => $start->daysInMonth,
+        ];
+    }
+
     /** @param array<string,mixed> $state */
     private function stateAnchor(array $state): string
     {
diff --git a/modules/EcommerceFinance/Repositories/ThirdPartyWarehouseStorageUpstreamRepository.php b/modules/EcommerceFinance/Repositories/ThirdPartyWarehouseStorageUpstreamRepository.php
index 6b623dd7..d80c3e97 100644
--- a/modules/EcommerceFinance/Repositories/ThirdPartyWarehouseStorageUpstreamRepository.php
+++ b/modules/EcommerceFinance/Repositories/ThirdPartyWarehouseStorageUpstreamRepository.php
@@ -12,7 +12,7 @@ class ThirdPartyWarehouseStorageUpstreamRepository
     /** 三方仓页面仍固定读取该仓；共享流水镜像覆盖全部仓库。 */
     public const WAREHOUSE_ID = 15045364;
 
-    public const START_DATE = '2026-08-01';
+    public const START_DATE = '2026-07-01';
 
     private ?UpstreamReadOnlyQuery $query = null;
 
diff --git a/tests/Unit/EcommerceFinance/ThirdPartyWarehouseStorageMirrorRepositoryTest.php b/tests/Unit/EcommerceFinance/ThirdPartyWarehouseStorageMirrorRepositoryTest.php
index 4c8b2c1a..b71ffe18 100644
--- a/tests/Unit/EcommerceFinance/ThirdPartyWarehouseStorageMirrorRepositoryTest.php
+++ b/tests/Unit/EcommerceFinance/ThirdPartyWarehouseStorageMirrorRepositoryTest.php
@@ -400,22 +400,30 @@ class ThirdPartyWarehouseStorageMirrorRepositoryTest extends TestCase
         $this->assertFalse($this->repository->allWarehousesReady());
     }
 
-    public function test_periods_before_the_supported_start_date_are_clamped(): void
+    public function test_monthly_inventory_report_supports_july_without_changing_flow_page_cutoff(): void
     {
         $this->markReady();
         $this->insertProduct('SKU-CUTOFF');
-        $this->insertInventory('SKU-CUTOFF', 2, '2026-08-02 00:00:00');
+        $this->insertInventory('SKU-CUTOFF', 10, '2026-08-01 00:00:00');
+        $this->insertMovement('SKU-CUTOFF', '采购进仓', 2, 1, '2026-07-15 12:00:00');
         $this->insertMovement('SKU-CUTOFF', '采购进仓', 2, 1, '2026-08-01 12:00:00');
 
         $day = $this->repository->paginate($this->filters([
             'dimension' => 'day',
             'period' => '2026-07-01',
         ]), 1, 25)['data'][0];
-        $month = $this->repository->paginate($this->filters(['period' => '2026-07']), 1, 100)['data'];
+        $inventoryReport = $this->repository->paginateMonthlyInventoryReport([
+            'month' => '2026-07',
+            'product_code' => 'SKU-CUTOFF',
+            'warehouse_provider' => '',
+            'category' => '',
+        ], 1, 25);
 
         $this->assertSame('2026-08-01', $day['date']);
-        $this->assertSame('2026-08-01', $month[0]['date']);
-        $this->assertSame('2026-08-31', $month[30]['date']);
+        $this->assertSame(1, $inventoryReport['total']);
+        $this->assertSame('2026-07-01', $inventoryReport['data'][0]->month);
+        $this->assertSame(8.0, (float) $inventoryReport['data'][0]->opening_quantity);
+        $this->assertSame(10.0, (float) $inventoryReport['data'][0]->closing_quantity);
     }
 
     public function test_product_catalog_must_finish_initial_sync_before_product_fields_are_exposed(): void