Hi Nagireddy,
The Invoices that you are sending as CSV files-does it contain line item level details or only header level details?
The Bill to party is a line item level partner detail and can be different for each line item. You can fetch the same from VBPA table passing the Partner Function, Billing document number and posnr = '000000' and if not found then by passing the Partner Function, Billing document number and posnr = invoice posnr (vbrp-posnr).
Regards,
Shashi Thakur