UPU World Numbering System

WNS aims at promoting the legal stamp market by allowing the public as well as all players in the philatelic market (catalogue publishers, collectors, stamp dealers, philatelic press) to verify the authenticity of their postage stamps.

The WNS website allows easier thematic search by collectors through themes and sub-themes accessible via a multi-country website.

It serves as a commercial tool to promote sales by providing direct links to the philatelic shops of designated operators around the world and fosters direct customer/dealer relationships.