diff --git a/server/AyaNova/biz/PurchaseOrderBiz.cs b/server/AyaNova/biz/PurchaseOrderBiz.cs
index 1f857728..7903f995 100644
--- a/server/AyaNova/biz/PurchaseOrderBiz.cs
+++ b/server/AyaNova/biz/PurchaseOrderBiz.cs
@@ -699,12 +699,15 @@ namespace AyaNova.Biz
         {
             var ThisPart = poParts.Single(x => x.Id == poItem.PartId);//part should always be there, if it isn't we have deeper problems
             //VendorPartNumber
-            if (ThisPart.ManufacturerId == vendorId)
-                poItem.VendorPartNumber = ThisPart.ManufacturerNumber;
-            else if (ThisPart.WholeSalerId == vendorId)
-                poItem.VendorPartNumber = ThisPart.WholeSalerNumber;
-            else if (ThisPart.AlternativeWholeSalerId == vendorId)
-                poItem.VendorPartNumber = ThisPart.AlternativeWholeSalerNumber;
+            if (string.IsNullOrWhiteSpace(poItem.VendorPartNumber))//only set if empty, user may have typed in one already on create
+            {
+                if (ThisPart.ManufacturerId == vendorId)
+                    poItem.VendorPartNumber = ThisPart.ManufacturerNumber;
+                else if (ThisPart.WholeSalerId == vendorId)
+                    poItem.VendorPartNumber = ThisPart.WholeSalerNumber;
+                else if (ThisPart.AlternativeWholeSalerId == vendorId)
+                    poItem.VendorPartNumber = ThisPart.AlternativeWholeSalerNumber;
+            }
 
             //Costs
             poItem.PurchaseOrderCost = ThisPart.Cost;