diff --git a/modules/purchase_trade/lot.py b/modules/purchase_trade/lot.py
index a96c452..7a3fc9a 100755
--- a/modules/purchase_trade/lot.py
+++ b/modules/purchase_trade/lot.py
@@ -5036,6 +5036,14 @@ class LotInvoiceStart(ModelView):
             if getattr(line, 'lot', None)]
         return self._split_sale_padding(self.sale_padding, lots)
 
+    @classmethod
+    def _split_sale_padding(cls, padding, lots):
+        padding = Decimal(str(padding or 0))
+        if not padding or not lots:
+            return {}
+        share = padding / Decimal(len(lots))
+        return {lot.id: share for lot in lots}
+
     @staticmethod
     def _record_key(record):
         return getattr(record, 'id', None) or id(record)