diff --git a/buying/doctype/purchase_common/purchase_common.js b/buying/doctype/purchase_common/purchase_common.js
index dfcafed..eee7984 100644
--- a/buying/doctype/purchase_common/purchase_common.js
+++ b/buying/doctype/purchase_common/purchase_common.js
@@ -309,6 +309,12 @@
 				delete item["rate"];
 			});
 		}
+		
+		if(!wn.meta.get_docfield(item.doctype, "item_tax_amount", item.parent || item.name)) {
+			$.each(this.frm.item_doclist, function(i, item) {
+				delete item["item_tax_amount"];
+			});
+		}
 	},
 	
 	calculate_outstanding_amount: function() {
@@ -326,9 +332,10 @@
 		// stored for valuation 
 		// 
 		// TODO: rename item_tax_amount to valuation_tax_amount
-		if(["Valuation", "Valuation and Total"].indexOf(tax.category) != -1) {
-			// accumulate only if tax is for Valuation / Valuation and Total
-			item.item_tax_amount += flt(current_tax_amount, precision("item_tax_amount", item));
+		if(["Valuation", "Valuation and Total"].indexOf(tax.category) != -1 &&
+			wn.meta.get_docfield(item.doctype, "item_tax_amount", item.parent || item.name)) {
+				// accumulate only if tax is for Valuation / Valuation and Total
+				item.item_tax_amount += flt(current_tax_amount, precision("item_tax_amount", item));
 		}
 	},
 	
diff --git a/controllers/buying_controller.py b/controllers/buying_controller.py
index 312fb8e..f1cfc10 100644
--- a/controllers/buying_controller.py
+++ b/controllers/buying_controller.py
@@ -167,7 +167,7 @@
 			for item in self.item_doclist:
 				item.purchase_rate = item.rate
 				del item.fields["rate"]
-				
+		
 		if not self.meta.get_field("item_tax_amount", parentfield=self.fname):
 			for item in self.item_doclist:
 				del item.fields["item_tax_amount"]
@@ -179,8 +179,9 @@
 			
 			TODO: rename item_tax_amount to valuation_tax_amount
 		"""
-		if tax.category in ["Valuation", "Valuation and Total"]:
-			item.item_tax_amount += flt(current_tax_amount, self.precision("item_tax_amount", item))
+		if tax.category in ["Valuation", "Valuation and Total"] and \
+			self.meta.get_field("item_tax_amount", parentfield=self.fname):
+				item.item_tax_amount += flt(current_tax_amount, self.precision("item_tax_amount", item))
 				
 	# update valuation rate
 	def update_valuation_rate(self, parentfield):