You can bill a shipment to a Third-Party by configuring a Third-Party Payment option with their Carrier Account in OrderCup and then selecting this Third-Party Payment option at the time of shipping for payment.
NOTE: In order to bill a shipment to a Third-Party Payment option, you would have to have that your own Carrier Account corresponding to that option so that the carrier services are enabled in OrderCup. For example if you want to bill a shipment to a Third-Party UPS Payment option, you will have to have your own UPS Account configured in OrderCup.
To set up a Third-Party Payment option in OrderCup:
1) Go to the Settings Tab
2) Click the Third-Party Payment link on the on left (under Stores).
3) Click on the New button and add the third-party payment account.
4) Fill in the account name, and other payment details.
5) Click the Save button and you are done.
Once you have set up a Third-Party payment option, you use this as a Payment Type when shipping a package on the Ship Tab.