diff --git a/application/Preorder/PreorderModel.php b/application/Preorder/PreorderModel.php
index 71d276c71..dc3603513 100644
--- a/application/Preorder/PreorderModel.php
+++ b/application/Preorder/PreorderModel.php
@@ -948,9 +948,9 @@ class PreorderModel
             }
         }
 
-        if (array_key_exists("billed", $filter)) {
+        if (array_key_exists("billed", $filter) && !empty($filter['billed'])) {
             $billed = $filter['billed'];
-            if ($billed == 0 || $billed === null) {
+            if ($billed == 0) {
                 $where .= " AND (tt_preorder.billed IS NULL OR tt_preorder.billed = 0)";
             } elseif ($billed) {
                 $where .= " AND tt_preorder.billed > 0";
@@ -1035,7 +1035,7 @@ class PreorderModel
             }
         }
 
-        if (array_key_exists("attributes_bep_specified", $filter)) {
+        if (array_key_exists("attributes_bep_specified", $filter) && !empty($filter['attributes_bep_specified'])) {
             if ($filter['attributes_bep_specified'] == 1) {
                 $where .= " AND JSON_EXTRACT(tt_preorder.attributes, \"$.bep_specified\") = 1";
             } else if ($filter['attributes_bep_specified'] == 0) {