Can I put a Landed Cost on a Drop-Ship PO in Microsoft Dynamics GP?
No. You can only add Landed costs to receivings, and drop-ship PO's are not received in and do not affect inventory since the quantities are shipped directly to the Customer's site. Because drop-ship PO's are not received, there will be no shipment receipt to enter the Landed Cost on and no shipment receipt to match the Landed Cost with. Landed costs are only added to receivings, and there is none in this case.
Work-around: If you wish to charge the customer an additional amount equivalent to the Landed Cost amount, you could add it as a 'Freight' Amount (and edit the GL account as desired).