All goods, including Free of Charge (FOC) items or replacement goods imported into Singapore, are subjected to Goods & Services Tax (GST). For items without any value indicated in the invoices, you have to obtain the commercial value of the items from the supplier/merchant. Therefore, the declared value at the time of import should be based on:

1. The transaction value of identical or similar goods from the same country of origin that is exported at about the same time, or
2. The original price payable for the goods as if they are sold for export to Singapore.

Please refer to Singapore Customs’ website or their circular on the valuation of goods declared for GST purposes.