diff --git a/includes/gateway/abstract-omise-payment-base-card.php b/includes/gateway/abstract-omise-payment-base-card.php
index 2707d17d..d61402a4 100644
--- a/includes/gateway/abstract-omise-payment-base-card.php
+++ b/includes/gateway/abstract-omise-payment-base-card.php
@@ -62,13 +62,14 @@ private function getOmiseCustomerId($user) {
 	private function prepareChargeData($order_id, $order, $omise_customer_id, $card_id, $token)
 	{
 		$currency = $order->get_currency();
+		$order_number = $order->get_order_number();
 		$data = [
 			'amount' => Omise_Money::to_subunit($order->get_total(), $currency),
 			'currency' => $currency,
-			'description' => 'WooCommerce Order id ' . $order_id,
+			'description' => 'WooCommerce Order id ' . $order_number,
 			'return_uri' => $this->get_redirect_url('omise_callback', $order_id, $order),
 			'metadata' => $this->get_metadata(
-				$order_id,
+				$order_number,
 				[ 'secure_form_enabled' => $this->getSecureFormState()]
 			),
 		];
diff --git a/includes/gateway/traits/charge-request-builder-trait.php b/includes/gateway/traits/charge-request-builder-trait.php
index 3ddd1e11..bdc04476 100644
--- a/includes/gateway/traits/charge-request-builder-trait.php
+++ b/includes/gateway/traits/charge-request-builder-trait.php
@@ -10,13 +10,14 @@ public function build_charge_request(
 	)
 	{
 		$currency = $order->get_currency();
-		$description = 'WooCommerce Order id ' . $order_id;
+		$order_number = $order->get_order_number();
+		$description = 'WooCommerce Order id ' . $order_number;
 
 		$request = [
 			'amount'      => Omise_Money::to_subunit($order->get_total(), $currency),
 			'currency'    => $currency,
 			'description' => $description,
-			'metadata'    => $this->get_metadata($order_id),
+			'metadata'    => $this->get_metadata($order_number),
 			'source' 	  => [ 'type' => $source_type ]
 		];
 
@@ -40,13 +41,13 @@ public function build_charge_request(
 	}
 
 	/**
-	 * @param string $order_id
+	 * @param string $order_number
 	 * @param array $additionalData
 	 */
-	public function get_metadata($order_id, $additionalData = [])
+	public function get_metadata($order_number, $additionalData = [])
 	{
 		// override order_id as a reference for webhook handlers.
-		$orderId = [ 'order_id' => $order_id ];
+		$orderId = [ 'order_id' => $order_number ];
 		return array_merge($orderId, $additionalData);
 	}
 
diff --git a/tests/unit/includes/gateway/abstract-omise-payment-base-card-test.php b/tests/unit/includes/gateway/abstract-omise-payment-base-card-test.php
index cff4a717..3a70ebdf 100644
--- a/tests/unit/includes/gateway/abstract-omise-payment-base-card-test.php
+++ b/tests/unit/includes/gateway/abstract-omise-payment-base-card-test.php
@@ -62,6 +62,8 @@ public function getOrderMock($expectedAmount, $expectedCurrency)
             ->andReturn($expectedAmount);  // in units
         $orderMock->shouldReceive('add_meta_data')
             ->andReturn(['order_id' => 'order_123']);
+        $orderMock->shouldReceive('get_order_number')
+            ->andReturn(1234);
         $orderMock->shouldReceive('get_user')
             ->andReturn((object)[
                 'ID' => 'user_123',
diff --git a/tests/unit/includes/gateway/traits/charge-request-builder-test.php b/tests/unit/includes/gateway/traits/charge-request-builder-test.php
index 3ffe5cc4..3366dcea 100644
--- a/tests/unit/includes/gateway/traits/charge-request-builder-test.php
+++ b/tests/unit/includes/gateway/traits/charge-request-builder-test.php
@@ -34,6 +34,8 @@ public function getOrderMock($expectedAmount, $expectedCurrency)
         $orderMock->shouldReceive('get_total')
             ->andReturn($expectedAmount);  // in units
         $orderMock->shouldReceive('add_meta_data');
+        $orderMock->shouldReceive('get_order_number')
+            ->andReturn(1234);
         return $orderMock;
     }