What I had done was to create a UDF in the Sales Order Invoice Header called CustName sourced from SO_Invoice_bus > CustomerNo > CustomerName. Then I added it to the Header Tab in a blank area at the bottom right, added it above the panels just to the right of Tab 4, and added it to the blank area to the right of the lower grid on the lines tab. No problems doing that but none of them populated. I figured the one outside the tab panels was failing to populate because that area is setup prior to even entering a customer but don't understand why the other to didn't work, especially the one where I just duplicated it on the Header panel.
After posting, I actually saved my test invoice and when I went back in to the invoice, the UDF outside the Tab Panel area populated. The UDFs on the Header Tab and Lines Tab did not. Not sure what I am doing wrong.
The reason the customer wanted the customer number or name to show is that she needs to quickly review the GL distribution from other peoples invoice entry prior to posting. The GL distribution corresponds to a global region and the customer name or number will tell her the region. Because the invoices have been accepted once prior to her review, the UDF outside the Tab Panels should solve this issue for this go around..