FYI:

This information only concern people with both ROC (Taiwan) passport and work permit.

When I first applied for work permit in June 2016, my nationality was changed from TAIWAN to CHINA by Labor office. When I objected, the Chiang Mai labor office said that since there is the word "CHINA" on my passport, I am Chinese. This caused me and my agent to change all the mentions of Taiwanese to Chinese on visa application.

Having applied for extension as Chinese three times, this year, my application was not accepted because the correct name is "CHINA TAIWAN". I was told to sent my work permit and letter from city government back to appropriate office for correction. According to the officer at Immigration Office, there were multiple inter-agency meetings on this matter. It is "CHINA TAIWAN".