Since Aug 1, Hainan has started labeling its offshore duty-free perfumes, cosmetics, liquors and mobile phones with traceability codes to safeguard the interests of customers and ensure a better shopping environment.

All the offshore duty-free goods in Hainan will be attached with traceability codes by the end of December. The codes are printed with warnings that prohibit customers from reselling the products.

The establishment of such system allows for the traceability of both a product's origin and whereabouts. Regulators can easily find people who resell goods illegally and hold them reliable, a Haikou Customs officer said.