diff --git a/app/Logic/ReceiptIssuingOrder/ReceiptIssuingOrderManager.php b/app/Logic/ReceiptIssuingOrder/ReceiptIssuingOrderManager.php
index 1ffa736..f7351fd 100644
--- a/app/Logic/ReceiptIssuingOrder/ReceiptIssuingOrderManager.php
+++ b/app/Logic/ReceiptIssuingOrder/ReceiptIssuingOrderManager.php
@@ -10,6 +10,7 @@ use App\Exceptions\ExclusiveException;
 use App\Features\InstanceAble;
 use App\Features\LoginUser;
 use App\Models\ReceiptIssuingOrder;
+use App\Models\ReceiptIssuingOrderSeqNumber;
 use App\Models\User;
 use App\Util\DateUtil;
 use Illuminate\Support\Carbon;
@@ -200,10 +201,29 @@ abstract class ReceiptIssuingOrderManager
         return $this;
     }
 
+    protected function fillSeqNumber(): static
+    {
+        if ($this->order->seq_number !== null) {
+            return $this;
+        }
+
+        $seq = ReceiptIssuingOrderSeqNumber::lockForUpdate()->first();
+        if (!($seq instanceof ReceiptIssuingOrderSeqNumber)) {
+            throw new AppCommonException("通番取得失敗");
+        }
+        $seq->seq_number++;
+        $this->order->seq_number = $seq->seq_number;
+        $seq->save();
+
+        return $this;
+    }
+
     protected function save(): static
     {
         $this->setStatus()
-            ->updateCheck();
+            ->updateCheck()
+            ->fillSeqNumber();
+
         $this->order->save();
         return $this;
     }
diff --git a/app/Models/ReceiptIssuingOrder.php b/app/Models/ReceiptIssuingOrder.php
index bf3dd56..d02ac67 100644
--- a/app/Models/ReceiptIssuingOrder.php
+++ b/app/Models/ReceiptIssuingOrder.php
@@ -55,6 +55,7 @@ class ReceiptIssuingOrder extends AppModel
     const COL_NAME_ACCEPT_PRIVACY_POLICY = "accept_privacy_policy";
     const COL_NAME_ACCEPT_CORRECT_ENTRY = "accept_correct_entry";
     const COL_NAME_ACCEPT_SITE_POLICY = "accept_site_policy";
+    const COL_NAME_SEQ_NUMBER = "seq_number";
 
     protected $casts = [
         self::COL_NAME_ORDER_DATETIME => 'datetime',
diff --git a/app/Models/ReceiptIssuingOrderSeqNumber.php b/app/Models/ReceiptIssuingOrderSeqNumber.php
new file mode 100644
index 0000000..2a0a279
--- /dev/null
+++ b/app/Models/ReceiptIssuingOrderSeqNumber.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace App\Models;
+
+
+class ReceiptIssuingOrderSeqNumber extends AppModel
+{
+
+    const COL_NAME_CONTRACT_ID = ColumnName::CONTRACT_ID;
+    const COL_NAME_SEQ_NUMBER = "seq_number";
+
+    public function getModelName(): string
+    {
+        return "領収証発行依頼通番管理";
+    }
+
+    public function getHistory(): ?HistoryModel
+    {
+        return null;
+    }
+}
diff --git a/database/migrations/2023_08_01_162900_add_column_receipt_issuing_orders_table_seq_no.php b/database/migrations/2023_08_01_162900_add_column_receipt_issuing_orders_table_seq_no.php
new file mode 100644
index 0000000..4273959
--- /dev/null
+++ b/database/migrations/2023_08_01_162900_add_column_receipt_issuing_orders_table_seq_no.php
@@ -0,0 +1,38 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('receipt_issuing_orders', function (Blueprint $table) {
+            $table->bigInteger("seq_number", false, true)->nullable()->comment("通番");
+        });
+        Schema::table('receipt_issuing_order_histories', function (Blueprint $table) {
+            $table->bigInteger("seq_number", false, true)->nullable()->comment("通番");
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::table('receipt_issuing_orders', function (Blueprint $table) {
+            $table->dropColumn("seq_number");
+        });
+        Schema::table('receipt_issuing_order_histories', function (Blueprint $table) {
+            $table->dropColumn("seq_number");
+        });
+    }
+};
diff --git a/database/migrations/2023_08_01_163700_create_receipt_issuing_order_seq_numbers_table.php b/database/migrations/2023_08_01_163700_create_receipt_issuing_order_seq_numbers_table.php
new file mode 100644
index 0000000..18561b1
--- /dev/null
+++ b/database/migrations/2023_08_01_163700_create_receipt_issuing_order_seq_numbers_table.php
@@ -0,0 +1,43 @@
+<?php
+
+use App\Models\ReceiptIssuingOrderSeqNumber;
+use App\Util\MigrationHelper;
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        MigrationHelper::createTable('receipt_issuing_order_seq_numbers', $this->schema());
+
+        ReceiptIssuingOrderSeqNumber::create([
+            ReceiptIssuingOrderSeqNumber::COL_NAME_SEQ_NUMBER => 0,
+        ]);
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::dropIfExists('receipt_issuing_order_seq_numbers');
+    }
+
+    private function schema()
+    {
+
+        return function (Blueprint $table,  MigrationHelper $helper) {
+            $helper->baseColumn();
+            $table->string('seq_number')->comment("通番");
+        };
+    }
+};