Field help (INVFCY) 

Site for which the invoices of this order are intended, initialized by default by the code of the financial site associated with the order site.
SEEWARNING This invoicing site is necessarily a financial site belonging to the same legal company as the order site.
This field is managed depending on the setup of theentry transaction of the subcontract order.

Inter-company specificities: In the case of an inter-company or inter-site order, the invoicing site is initialized to the site associated with the bill-to customer defined in the customer record for the purchase site. The invoicing site can be modified on the condition that it is associated with a customer. At the time of the sales order generation, the bill-to customer and the pay-by customer will be initialized to the customer associated with the invoicing site entered. In the case of a modification, the sales order will automatically be updated.