diff --git a/plugins/woocommerce/changelog/fix-order_type b/plugins/woocommerce/changelog/fix-order_type
new file mode 100644
index 00000000000..ba0073e6737
--- /dev/null
+++ b/plugins/woocommerce/changelog/fix-order_type
@@ -0,0 +1,4 @@
+Significance: patch
+Type: fix
+
+Check order type is set before returning to prevent notice.
diff --git a/plugins/woocommerce/src/Internal/DataStores/Orders/OrdersTableDataStore.php b/plugins/woocommerce/src/Internal/DataStores/Orders/OrdersTableDataStore.php
index 826cc0ce5c6..64885983ab5 100644
--- a/plugins/woocommerce/src/Internal/DataStores/Orders/OrdersTableDataStore.php
+++ b/plugins/woocommerce/src/Internal/DataStores/Orders/OrdersTableDataStore.php
@@ -948,7 +948,7 @@ WHERE
 	 */
 	public function get_order_type( $order_id ) {
 		$type = $this->get_orders_type( array( $order_id ) );
-		return $type[ $order_id ];
+		return $type[ $order_id ] ?? '';
 	}
 
 	/**
diff --git a/plugins/woocommerce/src/Internal/Utilities/COTMigrationUtil.php b/plugins/woocommerce/src/Internal/Utilities/COTMigrationUtil.php
index 1c88e5074b5..d0a17ffeb47 100644
--- a/plugins/woocommerce/src/Internal/Utilities/COTMigrationUtil.php
+++ b/plugins/woocommerce/src/Internal/Utilities/COTMigrationUtil.php
@@ -75,7 +75,7 @@ class COTMigrationUtil {
 	 */
 	public function is_custom_order_tables_in_sync() : bool {
 		$sync_status = $this->data_synchronizer->get_sync_status();
-		return $sync_status['current_pending_count'] === 0 && $this->data_synchronizer->data_sync_is_enabled();
+		return 0 === $sync_status['current_pending_count'] && $this->data_synchronizer->data_sync_is_enabled();
 	}
 
 	/**
@@ -160,7 +160,7 @@ class COTMigrationUtil {
 	 *
 	 * @return string|null Type of the order.
 	 */
-	public function get_order_type( $order_id ) : ?string {
+	public function get_order_type( $order_id ) {
 		$order_id         = $this->get_post_or_order_id( $order_id );
 		$order_data_store = \WC_Data_Store::load( 'order' );
 		return $order_data_store->get_order_type( $order_id );
diff --git a/plugins/woocommerce/tests/php/src/Internal/DataStores/Orders/OrdersTableDataStoreTests.php b/plugins/woocommerce/tests/php/src/Internal/DataStores/Orders/OrdersTableDataStoreTests.php
index 37f4f850469..3b512c14328 100644
--- a/plugins/woocommerce/tests/php/src/Internal/DataStores/Orders/OrdersTableDataStoreTests.php
+++ b/plugins/woocommerce/tests/php/src/Internal/DataStores/Orders/OrdersTableDataStoreTests.php
@@ -1868,6 +1868,23 @@ class OrdersTableDataStoreTests extends WC_Unit_Test_Case {
 		$this->assertFalse( wc_get_order( $product->get_id() ) );
 	}
 
+	/**
+	 * @testDox Make sure that getting order type for non order return without warning.
+	 */
+	public function test_get_order_type_for_non_order() {
+		$product = WC_Helper_Product::create_simple_product();
+		$product->save();
+		$this->assertEquals( '', $this->sut->get_order_type( $product->get_id() ) );
+	}
+
+	/**
+	 * @testDox Test get order type working as expected.
+	 */
+	public function test_get_order_type_for_order() {
+		$order = $this->create_complex_cot_order();
+		$this->assertEquals( 'shop_order', $this->sut->get_order_type( $order->get_id() ) );
+	}
+
 	/**
 	 * @testDox Test that we are not duplicating address indexing when updating.
 	 */