I'm not a big fan of Vpost because they always over-charge the shipment. Same package same vendor I sent via Comgateway will cause me SGD40ish. But if I use Vpost, it will definitely cause me SGD60 and above. Vpost will always repack your shipment and charge you SGD12 too (though they guarantee I will save on shipping).
Anyway those who still support Vpost will definitely need the code