diff --git a/erpnext/controllers/taxes_and_totals.py b/erpnext/controllers/taxes_and_totals.py
index 42cd7de..2144055 100644
--- a/erpnext/controllers/taxes_and_totals.py
+++ b/erpnext/controllers/taxes_and_totals.py
@@ -309,7 +309,7 @@
 	def calculate_shipping_charges(self):
 
 		# Do not apply shipping rule for POS
-		if self.doc.is_pos:
+		if self.doc.get("is_pos"):
 			return
 
 		if hasattr(self.doc, "shipping_rule") and self.doc.shipping_rule: