From Expense reimbursement discussion:
Sometimes you need to delegate the purchase of goods, but the invoice need to be in the company name.
It can also be useful if the customer delegate someone (the customer accountant for example), to keep track who need to pay the invoice on behalf of the customer.
For this reason it wold be useful to have a “delegated to party” field in the invoice.
Theory of operation
When you post the invoice it will also create a payable move on behalf of the delegated party (if the field is not empty), and it will considered the invoice paid.
When you post the invoice it will generate also a receivable move for the delegated party.
In this case the invoice will not be automatically paid until the receivable move is not reconciled