http://www.customs.go.th/Customs-Eng...menuNme=Travel
A strict reading indicates you have to declare anything over 10,000 baht - but that is ridiculous in terms of vast experiences and practical enforcement. That would require the declaration of virtually every laptop and camera.
Green Channel (nothing to declare):
Personal belonging in reasonable amount for owner’s use and the total value not exceeding 10,000 baht.
( not restricted/prohibited items or provision)
(emphasis mine)
Red Channel (need to declare):
1. Dutiable items
* items that you did not have when you left Thailand and their quantities are not reasonable for personal use or/and the total value of belongings is more than 10,000 baht.
* items that are intended for commercial use, business, or trade purposes e.g. molds
The language in the second suggests this is only for returning Thai residents, but the language in the first has no such qualifier and the page is written in English for all travelers.
For a slightly less confusing, but still somewhat contradictory when read in its entirety, explanation from the Thai government, please see
http://canberra.thaiembassy.org/doc/...ai_customs.pdf
1.2 Personal effects which accompany passengers in an amount not exceeding their needs for personal or professional use and with the total value of all goods taken together not exceeding 10,000 baht, will be exempted from Customs duties. Personal effects such as clothing, cosmetics, jewelry, shoes, glasses, perfumes, etc., purchased abroad must have a receipt as evidence of the value; if not, the Customs officer will consider other available evidence.