One principal business and one subsidiary with separate bank accounts. Both have a shared expense. While "entering bill" cost is allocated to both and their respective classes (Principal and Subsidiary) applied respectively. Check is written from the principal business.
Now we have to write a check from the subsidiary to the principal business to pay off the liability created.
Account column: Payee
Class column: ????...Should this be the Principal business or the subsidiary? Why?
Most companies with intercompany subsidiaries do not bother to trade cash back and forth since no need.
If ultimately the financial statements will be consolidated, there is really no need for the extra accounting.
Most often we see intercompany TO/FROM accounts and maybe transfer cash once a year at year end but assuming you need separate balance sheets for each entity for some reason, and using classes to do that, then it would seem for a payment from one to the other that would be a debit one class and credit other.