diff --git a/app/Utils/HtmlEngine.php b/app/Utils/HtmlEngine.php
index d663dd0dfa5e..be7d3612019e 100644
--- a/app/Utils/HtmlEngine.php
+++ b/app/Utils/HtmlEngine.php
@@ -134,11 +134,13 @@ class HtmlEngine
         
         $data['$dueDate'] = &$data['$due_date'];
 
+
         $data['$payment_due'] = ['value' => $this->translateDate($this->entity->due_date, $this->client->date_format(), $this->client->locale()) ?: ' ', 'label' => ctrans('texts.payment_due')];
         $data['$invoice.due_date'] = &$data['$due_date'];
         $data['$invoice.number'] = ['value' => $this->entity->number ?: ' ', 'label' => ctrans('texts.invoice_number')];
         $data['$invoice.po_number'] = ['value' => $this->entity->po_number ?: ' ', 'label' => ctrans('texts.po_number')];
         $data['$poNumber'] = &$data['$invoice.po_number'];
+        $data['$po_number'] = &$data['$invoice.po_number'];
         $data['$entity.datetime'] = ['value' => $this->formatDatetime($this->entity->created_at, $this->client->date_format(), $this->client->locale()), 'label' => ctrans('texts.date')];
         $data['$invoice.datetime'] = &$data['$entity.datetime'];
         $data['$quote.datetime'] = &$data['$entity.datetime'];
diff --git a/app/Utils/VendorHtmlEngine.php b/app/Utils/VendorHtmlEngine.php
index 88e0cff63d7a..b32e447e6c36 100644
--- a/app/Utils/VendorHtmlEngine.php
+++ b/app/Utils/VendorHtmlEngine.php
@@ -147,6 +147,7 @@ class VendorHtmlEngine
 
         $data['$entity.datetime'] = ['value' => $this->formatDatetime($this->entity->created_at, $this->company->date_format()), 'label' => ctrans('texts.date')];
 
+        $data['$po_number'] = &$data['$poNumber'];
         $data['$entity'] = ['value' => '', 'label' => ctrans('texts.purchase_order')];
         $data['$number'] = ['value' => $this->entity->number ?: ' ', 'label' => ctrans('texts.purchase_order_number')];
         $data['$number_short'] = ['value' => $this->entity->number ?: ' ', 'label' => ctrans('texts.purchase_order_number_short')];