One of Thailand customer inform me today they have the APEC Card and don't need the invitation letter for applying visa,

What is APEC Business Travel Card? I am curious,

Most APEC economies are full participating economies in the APEC Business Travel Card: Australia, Brunei Darussalam, Chile, China, Hong Kong, Indonesia, Japan, South Korea, Malaysia, Mexico, New Zealand, Papua New Guinea, Peru, the Philippines, Singapore, Taiwan, Thailand and Vietnam.^[1] Russia began full participation on 1 June 2013.^[2][3]

Citizens of these economies can apply for a Card at their national government, upon which moment their names are circulated amongst the other participating economies which give entry pre-clearance when all conditions are met. After this moment, the card can be used for visa-free entry.

Two economies are transitional members: United States and Canada. This permits them to issue APEC cards to their own citizens and nationals (who can benefit from visa-free travel to other APEC members) without having to grant visa-free travel status to citizens and nationals of other APEC members (though they may benefit from expedited border crossings and/or visa appointments from the United States and Canada).^[4] However, as of Sep 2013, neither the United States nor Canada has begun issuing the APEC cards, though domestic legislation permitting the program has passed in the United States.^[5]

It is also possible for a citizen of a third party country (including the United States and Canada) who is also permanent resident of Hong Kong to apply via Hong Kong immigration; for example a British citizen who is a permanent resident of Hong Kong can apply via the Hong Kong Immigration Department for an APEC card. This exception does not apply to any other member countries