diff --git a/alkatorapi/views.py b/alkatorapi/views.py
index f2694b2..6318ede 100644
--- a/alkatorapi/views.py
+++ b/alkatorapi/views.py
@@ -19,7 +19,7 @@ import PIL.Image
 import random
 from collections import OrderedDict
 
-from .models import User, ALKATOR_CHOICES_DICT, ALKATOR_CLASSES, Profile, Racer, Invoice, Product
+from .models import User, ALKATOR_CHOICES_DICT, ALKATOR_CLASSES, Profile, Racer, Invoice, Product, InvoiceProduct
 from alkator.settings import COMGATE_MERCHANT, COMGATE_SECRET, COMGATE_TEST
 
 
@@ -113,8 +113,6 @@ def register_racer(request):
     if product.quantity <= 0:
         return HttpResponse('{"reason":"Jsme vyprodaní!"}', status=400, content_type='application/json')
 
-    product.quantity -= 1
-    product.save()
 
     invoice = Invoice(
         invoice_id=invoice_id,
@@ -148,7 +146,7 @@ def register_racer(request):
         'label': 'Startovné na závod Alkátor Race Dolní Čermná 2025',
         'email': user.email,
         'fullName': f"{profile.first_name} {profile.last_name}",
-        'refId': f'{racer.invoice_id}',
+        'refId': f'{invoice.invoice_id}',
         'secret': COMGATE_SECRET,
         'prepareOnly': 'true',
     }
@@ -161,6 +159,9 @@ def register_racer(request):
         invoice.delete()
         return HttpResponse('{"reason":"Chyba na straně platební brány: ' + result['message'][0] + ', zkuste prosím registraci později."}', status=400, content_type='application/json')
 
+    product.quantity -= 1
+    product.save()
+
     invoice.trans_id = result['transId'][0]
     invoice.save()