I was asked to examine years of sales order history and to explain why the sales tax amount on an order is different than the sale tax amount on the corresponding invoice. Out of hundreds of thousands of orders being transferred to invoices I found 132 occurrences of this. They do have a custom program that takes orders off the web and inserts them into GP. These orders are then transferred to invoices. Nothing changes from the order to the invoice. The customer and address is the same as is the lines on the order. One thing I did not is that no sales tax schedule is assigned to the orders however if you zoom to the sales tax detail you will see the correct sales tax detail total and percentage amount. I do not have access to the custom code server but I was told they are using eConnect to import the orders. This is GP 2010.