diff --git a/app/Mail/Engine/PaymentEmailEngine.php b/app/Mail/Engine/PaymentEmailEngine.php
index f2fd269c42d6..4b18ef43ef68 100644
--- a/app/Mail/Engine/PaymentEmailEngine.php
+++ b/app/Mail/Engine/PaymentEmailEngine.php
@@ -240,6 +240,9 @@ class PaymentEmailEngine extends BaseEmailEngine
         $data['$invoices'] = ['value' => $this->formatInvoices(), 'label' => ctrans('texts.invoices')];
         $data['$invoice_references'] = ['value' => $this->formatInvoiceReferences(), 'label' => ctrans('texts.invoices')];
         $data['$invoice'] = ['value' => $this->formatInvoice(), 'label' => ctrans('texts.invoices')];
+        $data['$invoice.po_number'] = ['value' => $this->formatPoNumber(), 'label' => ctrans('texts.po_number')];
+        $data['$poNumber'] = &$data['$invoice.po_number'];
+
         return $data;
     }
 
@@ -253,6 +256,16 @@ class PaymentEmailEngine extends BaseEmailEngine
         return $invoice;
     }
 
+    private function formatPoNumber()
+    {
+        $invoice = '';
+
+        if($this->payment->invoices()->exists())
+            $invoice = ctrans('texts.po_number_short') . implode(",", $this->payment->invoices->pluck('po_number')->toArray());
+
+        return $invoice;
+    }
+
     private function formatInvoices()
     {
         $invoice_list = '<br><br>';