diff --git a/User.php b/User.php
index 9fe4899..2cc395c 100644
--- a/User.php
+++ b/User.php
@@ -36,6 +36,7 @@
     public float $total_due;
     public $invoice;
     public bool $presentation_confirmed;
+    public $amount_open;
 
     function __construct()
     {
@@ -71,6 +72,7 @@
         $this->total_due = 0.0;
         $this->invoice = "";
         $this->presentation_confirmed = false;
+        $this->amount_open = 0.0;
     }
 
     function set_name_and_paper_id($first_name, $last_name, $paper_id): User