The importer or its authorized customs agent will apply for a Customs Import Permit (which is similar in nature to the import customs declaration step in other countries) through Singapore's national single window for trade declarations (TradeNet - https://www.tradenet.gov.sg/tradenet/).

After all duties and fees have been paid, the application for the Customs Import Permit will be approved with a specified validity period. The importer must present the Customs Import Permit (within its validity period) together with commercial documents (invoice, packing list, bill of lading, etc.) for customs clearance. In the case of seaborne containerized imports, however, the importer is not required to present printed copies of the customs permit and commercial documents to customs officers at the port of entry for verification.

Source: Center for WTO and International Trade - VCCI

• Import procedures and formalities in Singapore
• Preparation for importing into Singapore
• Classification of goods imported into Singapore
• Determine taxes and fees on imports into Singapore