In "Delivered duty paid" means that the seller fulfils his obligation to deliver when the goods have been made available at the named place in the country of importation. The seller has to bear the risks and costs, including duties, taxes and other charges of delivering the goods thereto, cleared for importation. Whilst the Ex- Work term represents the minimum obligation for the seller, DDP represents the maximum obligation. This term should not be used if the seller is unable directly or indirectly lo obtain the import license. If the parties wish the buyer to clear the goods for importation and to pay the duty, the term DDU should be used. If the parties wish to exclude from the seller's obligations some of the costs payable upon importation of the goods (such as value added tax(VAT)), this should be made clear by adding words to this effect: "Delivered duty paid, VAT unpaid ... (named place of destination)".This term may be used irrespective of the mode of transport.
In "Delivered duty unpaid" means that the seller fulfils his obligation to deliver when the goods have been made available at the named place in the country of importation. The seller has to bear the costs and risks involved in bringing the goods thereto (excluding duties, taxes and other official charges payable upon importation) as well as the costs and risks of carrying out customs formalities. The buyer has to pay any additional costs and to bear any risks caused by his failure to clear the goods for import in time. This kind of shipments are normally made by companies for same shipments used for clinical trials etc or mainly by engineering companies where they serve the customer under warrantee/guarantee clause of their contracts.