diff --git a/app/Http/Controllers/Admin/SalesController.php b/app/Http/Controllers/Admin/SalesController.php
index 5f41984..e328e4c 100644
--- a/app/Http/Controllers/Admin/SalesController.php
+++ b/app/Http/Controllers/Admin/SalesController.php
@@ -1030,7 +1030,7 @@ class SalesController extends Controller
                         $row = [
                             $inv->invoice_no ?: '---',
                             $inv->invoice_date ?: '---',
-                            $inv->flow_id ?: '---',
+                            $inv->display_flow_id ?: '---',
                             $inv->machine->name ?? ($inv->order->machine->name ?? 'Unknown'),
                             $inv->machine->serial_no ?? ($inv->order->machine->serial_no ?? '---'),
                             $inv->order->order_no ?? '---',
diff --git a/app/Models/Transaction/Invoice.php b/app/Models/Transaction/Invoice.php
index 2fb7991..f802f44 100644
--- a/app/Models/Transaction/Invoice.php
+++ b/app/Models/Transaction/Invoice.php
@@ -6,13 +6,14 @@ use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\SoftDeletes;
 use App\Traits\TenantScoped;
+use App\Traits\HasDisplayFlowId;
 
 class Invoice extends Model
 {
     // TenantScoped：自動以登入者 company_id 過濾（含 route-model binding 與列表查詢），
     // 防止跨公司讀取/操作他人發票。console（佇列 Job / reconcile 命令）會自動跳過 scope，
     // 系統身分仍可跨公司開立/對帳。
-    use HasFactory, SoftDeletes, TenantScoped;
+    use HasFactory, SoftDeletes, TenantScoped, HasDisplayFlowId;
 
     protected $fillable = [
         'company_id',
diff --git a/app/Models/Transaction/Order.php b/app/Models/Transaction/Order.php
index 5f6ccbb..d8840ce 100644
--- a/app/Models/Transaction/Order.php
+++ b/app/Models/Transaction/Order.php
@@ -6,12 +6,13 @@ use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\SoftDeletes;
 use App\Traits\TenantScoped;
+use App\Traits\HasDisplayFlowId;
 use App\Models\Machine\Machine;
 use App\Models\Member\Member;
 
 class Order extends Model
 {
-    use HasFactory, SoftDeletes, TenantScoped;
+    use HasFactory, SoftDeletes, TenantScoped, HasDisplayFlowId;
 
     // 支付狀態
     public const PAYMENT_STATUS_FAILED = 0;
diff --git a/app/Traits/HasDisplayFlowId.php b/app/Traits/HasDisplayFlowId.php
new file mode 100644
index 0000000..4088b1f
--- /dev/null
+++ b/app/Traits/HasDisplayFlowId.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Traits;
+
+/**
+ * 提供「給人看的 flow_id」accessor：去掉機台序號前綴，顯示乾淨易讀的機台流水號。
+ *
+ * 資料庫仍儲存完整的 `serial_no . flow_id`（全域唯一值），供後台去重 / 冪等 / 對帳判斷使用；
+ * 此 accessor 只用於畫面與匯出顯示，不改動任何 DB 值。
+ *
+ * flow_id 格式：serial_no . YYYYMMDDHHMMSSXXXX（無分隔符）。
+ * 套用此 trait 的 Model 需具備 `flow_id` 欄位與 `machine`（含 serial_no）關聯。
+ */
+trait HasDisplayFlowId
+{
+    public function getDisplayFlowIdAttribute(): string
+    {
+        $flowId = (string) ($this->flow_id ?? '');
+        $serial = $this->machine?->serial_no;
+
+        // 僅在確實以該機台序號開頭時才剝除前綴；舊的未前綴資料原樣顯示（防禦）。
+        if ($serial !== null && $serial !== '' && str_starts_with($flowId, $serial)) {
+            return substr($flowId, strlen($serial));
+        }
+
+        return $flowId;
+    }
+}
diff --git a/resources/views/admin/sales/partials/order-detail-panel.blade.php b/resources/views/admin/sales/partials/order-detail-panel.blade.php
index cc457f6..d93a9ca 100644
--- a/resources/views/admin/sales/partials/order-detail-panel.blade.php
+++ b/resources/views/admin/sales/partials/order-detail-panel.blade.php
@@ -102,7 +102,8 @@
             </div>
             <div class="space-y-1">
                 <p class="text-[10px] font-black text-slate-400 dark:text-slate-500 uppercase tracking-widest">{{ __('Machine Flow ID') }}</p>
-                <p class="text-xs font-black text-slate-400 dark:text-slate-500 font-mono uppercase tracking-widest">{{ $order->flow_id }}</p>
+                {{-- 顯示去前綴序號的乾淨流水號（DB 仍存完整 serial+flow_id 唯一值供後台判斷） --}}
+                <p class="text-xs font-black text-slate-400 dark:text-slate-500 font-mono uppercase tracking-widest">{{ $order->display_flow_id }}</p>
             </div>
         </div>
     </section>
diff --git a/tests/Feature/Transaction/FinalizeIdempotencyTest.php b/tests/Feature/Transaction/FinalizeIdempotencyTest.php
index 684610a..ec9480c 100644
--- a/tests/Feature/Transaction/FinalizeIdempotencyTest.php
+++ b/tests/Feature/Transaction/FinalizeIdempotencyTest.php
@@ -101,6 +101,20 @@ class FinalizeIdempotencyTest extends TestCase
         $this->assertEquals('2222222222' . $raw, $orderB->flow_id);
     }
 
+    /** display_flow_id 顯示用 accessor:剝除機台序號前綴,DB 仍存完整 serial+raw 唯一值。 */
+    public function test_display_flow_id_strips_serial_prefix(): void
+    {
+        $serial = '2501000062';
+        $raw = '202606190839470011';
+        $this->makeMachine($serial);
+
+        $order = $this->service->finalizeTransaction($this->completedPayload($serial, $raw));
+
+        // DB 值維持完整 28 碼;顯示值剝掉序號前綴 → 乾淨 18 碼
+        $this->assertEquals($serial . $raw, $order->flow_id);
+        $this->assertEquals($raw, $order->fresh()->display_flow_id);
+    }
+
     /** RelateNumber = serial + rawFlowId(無分隔符、≤30、與線上推導逐字等價,不可雙重 serial)。 */
     public function test_relate_number_equals_serial_plus_raw_flow_id(): void
     {