Singapore filed one electronic form and customs answered in minutes.

In the 1980s Singapore's traders dealt with customs, the Trade Development Board and around 35 controlling agencies, filing 3–35 paper documents per shipment across roughly 10,000 declarations a day; each permit could take four hours to a week.

Singapore contracted the state-owned Singapore Network Services (later CrimsonLogic) to build TradeNet, launched on 1 January 1989 as the world's first national single window. One electronic declaration is routed to all agencies over a shared network, cutting permit processing to about ten minutes and fees per application from US$6.25 per document to US$1.80.

Freight forwarders reported 25–35% savings in trade-document handling time; because approvals moved from post-hoc to pre-approval, customs duties were collected faster through pre-paid electronic settlement.