diff --git a/services/nginx/app/objects/customer_vehicles_o.php b/services/nginx/app/objects/customer_vehicles_o.php
index e63a5746..baafaabb 100644
--- a/services/nginx/app/objects/customer_vehicles_o.php
+++ b/services/nginx/app/objects/customer_vehicles_o.php
@@ -490,18 +490,19 @@ class customer_vehicles_o extends db
             return [];
         }
         //print_r($transaction_ids);
-        // Convert the array of transaction ids to a comma separated string
-        $orders = '';
+        $orders = [];
         foreach ($transaction_ids as $transaction_id) {
             // Check if the transaction is included in the invoicing.
             $tmp = (new orders_o())->select((int)$transaction_id);
             if (!$tmp->isIncludedInInvoicing()) {
                 continue; // The transaction is not included in the invoicing, skip it
             }
-            $orders .= (int)$transaction_id . ',';
+            $orders[] = (int)$transaction_id;
         }
-        // Remove the last comma
-        $orders = rtrim($orders, ',');
+        if (empty($orders)) {
+            return [];
+        }
+        $order_ids = implode(',', $orders);
         // Get the first two transactions that are not deleted and contains at least one order item with the 'product_id' of the vehicle type for the vehicle
         $query = "
             SELECT o.id
@@ -509,7 +510,7 @@ class customer_vehicles_o extends db
             JOIN order_items oi ON oi.order_id = o.id
             WHERE o.deleted_at IS NULL
             AND oi.deleted_at IS NULL
-            AND o.id IN ($orders)
+            AND o.id IN ($order_ids)
             AND oi.product_id = " . (int)$this->type->value() . "
             GROUP BY o.id
             ORDER BY o.created_at ASC
diff --git a/services/nginx/app/tests/Unit/Invoicing/WashSubscriptionDistributionSqlGuardTest.php b/services/nginx/app/tests/Unit/Invoicing/WashSubscriptionDistributionSqlGuardTest.php
new file mode 100644
index 00000000..8e58ff6f
--- /dev/null
+++ b/services/nginx/app/tests/Unit/Invoicing/WashSubscriptionDistributionSqlGuardTest.php
@@ -0,0 +1,15 @@
+<?php
+
+it('does not query subscription-applied transactions with an empty eligible order list', function (): void {
+    $content = file_get_contents(dirname(__DIR__, 3) . '/objects/customer_vehicles_o.php');
+
+    expect($content)->not->toBeFalse();
+    $content = (string)$content;
+
+    expect($content)
+        ->toContain('$orders = [];')
+        ->toMatch('/\$orders\[\] = \(int\)\$transaction_id;\s*}\s*if \(empty\(\$orders\)\) {\s*return \[\];\s*}\s*\$order_ids = implode/s')
+        ->toContain('AND o.id IN ($order_ids)')
+        ->not->toContain('rtrim($orders, \',\')')
+        ->not->toContain('AND o.id IN ($orders)');
+});