Duty-free cigarettes are exempt from excise duty
Duty-free cigarettes are restricted to duty-free shops, and are generally only sold in duty-free cigarette shops at airports, and are not subject to GST.

The principle of duty-free sales was established by the 1954 New York Convention on International Travel: duty-free shops are the channels for showcasing brands, the window to the world, and brands can compete fairly in duty-free shops.