diff --git a/RIGS/finance.py b/RIGS/finance.py
index c8a3657d..fb075684 100644
--- a/RIGS/finance.py
+++ b/RIGS/finance.py
@@ -13,7 +13,8 @@ class InvoiceIndex(generic.ListView):
     template_name = 'RIGS/invoice_list.html'
 
     def get_queryset(self):
-        active = self.model.objects.filter(void=False).select_related('payment_set')
+        active = self.model.objects.filter(void=False).select_related('payment_set', 'event').prefetch_related(
+            'event__items').defer('event__person', 'event__organisation', 'event__venue', 'event__mic')
         set = []
         for invoice in active:
             if invoice.balance != 0:
diff --git a/RIGS/models.py b/RIGS/models.py
index 54b74ce5..b5b9a8da 100644
--- a/RIGS/models.py
+++ b/RIGS/models.py
@@ -248,7 +248,7 @@ class Event(models.Model, RevisionMixin):
     @property
     def sum_total(self):
         total = 0
-        for item in self.items.all():
+        for item in self.items.filter(cost__gt=0):
             total += item.total_cost
         return total
 
@@ -329,9 +329,9 @@ class Invoice(models.Model):
 
     @property
     def payment_total(self):
-        total = 0
-        for payment in self.payment_set.all():
-            total += payment.amount
+        total = self.payment_set.aggregate(models.Sum('amount'))
+        # for payment in self.payment_set.all():
+        #     total += payment.amount
         return total
 
     @property
@@ -352,11 +352,13 @@ class Payment(models.Model):
     INTERNAL = 'I'
     EXTERNAL = 'E'
     SUCORE = 'SU'
+    ADJUSTMENT = 'T'
     METHODS = (
         (CASH, 'Cash'),
         (INTERNAL, 'Internal'),
         (EXTERNAL, 'External'),
         (SUCORE, 'SU Core'),
+        (ADJUSTMENT, 'TEC Adjustment'),
     )
 
     invoice = models.ForeignKey('Invoice')