The account holder is chosen in the following order:
In the Financial relations screen, under the tab Transport -> Emballage, the balance holder determination can also be set. However, this is the same field as in the Relations screen
When you know which account ruleset is chosen, you can run through it to find out which rule is applied.
When it has been set that the ordergiver is the account party, you can specify whether Transpas uses the debtor or the ordergiver of a shipment in the emballage group.