From my research, there seem to be no official digital sources providing information on Thailand’s borders, administrative levels, and national parks. A quick comparison of various map providers like Google, Bing, Apple, Longdo, and the Royal Thai Survey shows discrepancies.
I discovered this dataset a few years ago. I have used it to check or validate the boundaries between Thailand and Myanmar but never pursued trying to make it legal. I don’t have the patience necessary to deal with either the OSM administrators or Humanitarian Data Exchange, the compilers of the boundary data.
It is a very comprehensive dataset as you’ll see when you look at this page,Humdata Thailand which contains links to only Thailand data.
The download link for those shapefiles can be found on the page linked below. It’s the second dataset from the top of the list: Thailand - Subnational Administrative Boundaries
Thailand administrative level 0 (country), 1 (province), 2 (district), and 3 (sub-district, tambon) boundaries
This data is apparently owned or administered by an affiliated organization called OCHA. I never contacted that organization but if you’re interested and have some time, I encourage someone to do that. This would be an invaluable dataset for OSM mappers if it could be made legally available.
Hi. Haven’t checked in in a long time (got an email notification when you linked an old post of mine in the service=alley thread the other day). The forum sure looks different.
Anyway, there certainly are official datasets for Thailand’s administrative boundaries and other stuff. They’re available at GISTDA Portal, https://gistdaportal.gistda.or.th/. The admin boundaries are under this tag, and here are forests and protected areas. The problem that’s kept them from being imported is that the government has been really muddy on the use conditions, and even with data that’s explicitly under Thailand’s Open Government License, there still are attached conditions that are likely incompatible with OSM’s terms.
The One Map project I understand is supposed to unify the different agencies’ digital data for law enforcement purposes, so it might not be publicly accessible.