diff --git a/server/generator/SockBotProcessPurchases.cs b/server/generator/SockBotProcessPurchases.cs
index 4575034..07c6caf 100644
--- a/server/generator/SockBotProcessPurchases.cs
+++ b/server/generator/SockBotProcessPurchases.cs
@@ -161,6 +161,12 @@ namespace Sockeye.Biz
 
                 var salesOrderNumber = jData["order_notification"]["purchase"]["purchase_id"].Value<string>();
 
+                if (await ct.Purchase.AnyAsync(z => z.SalesOrderNumber == salesOrderNumber))
+                    throw new System.ApplicationException($"Sales order already exists: {salesOrderNumber} will not be processed");
+
+                //ok, turn this into a fully realized Purchase record
+
+
             }
             catch (Exception ex)
             {