diff --git a/app/Http/Controllers/OnlinePaymentController.php b/app/Http/Controllers/OnlinePaymentController.php
index f30c47b87090..61526a616343 100644
--- a/app/Http/Controllers/OnlinePaymentController.php
+++ b/app/Http/Controllers/OnlinePaymentController.php
@@ -162,7 +162,8 @@ class OnlinePaymentController extends BaseController
     private function completePurchase($invitation, $isOffsite = false)
     {
         if ($redirectUrl = session('redirect_url:' . $invitation->invitation_key)) {
-            return redirect()->to($redirectUrl . '?invoice_id=' . $invitation->invoice->public_id);
+            $separator = strpos($redirectUrl, '?') === false ? '?' : '&';
+            return redirect()->to($redirectUrl . $separator . 'invoice_id=' . $invitation->invoice->public_id);
         } else {
             // Allow redirecting to iFrame for offsite payments
             return redirect()->to($invitation->getLink('view', ! $isOffsite));
diff --git a/resources/lang/en/texts.php b/resources/lang/en/texts.php
index 850cd8d4062c..d60bf3466a3f 100644
--- a/resources/lang/en/texts.php
+++ b/resources/lang/en/texts.php
@@ -2256,7 +2256,7 @@ $LANG = array(
     'force_pdfjs_help' => 'Replace the built-in PDF viewer in :chrome_link and :firefox_link.<br/>Enable this if your browser is automatically downloading the PDF.',
     'force_pdfjs' => 'PDF Viewer',
     'redirect_url' => 'Redirect URL',
-    'redirect_url_help' => 'Optionally specify a URL to redirect to after a payment is made.',
+    'redirect_url_help' => 'Optionally specify a URL to redirect to after a payment is made entered.',
 
 );