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Join Date: Sep 2009
Location: Minneapolis: DL DM charter 2.3MM
Programs: A3*Gold, SPG Plat, HyattDiamond, MarriottPP, LHW exAccess, ICI, Raffles Amb, NW PE MM, TWA Gold MM
Posts: 102,617
Exactly. For immigration and customs purposes, as well as for money, Hong Kong is treated like a separate country.
It's a bit like arriving in the USA. Even if the bag is checked through to your final destination, you must still walk it through customs before handing it back to the airline, even if it is already tagged to your final destination.