Enter the customer code for the customer to which the invoice basis should be linked. By default, the system applies the same code that was entered at the top of the order header, but you can also enter another customer code if needed.
In other words, a particular customer can entered as the customer buying the goods, but the invoice may be registered on another customer. The customer that was entered in this field will then be registered in the Accounts Receivable ledger, while the sales statistics will be updated for the customer that was entered under "Customer code" at the top of the Order header.