The Employment Service Act states in Art. 43 that
but does not define work. The Council of Labor Affairs (predecessor to the Ministry of Labor) clarified in 2005 in an interpretation letter (勞職外字第0940503946號函) that an activity does not require a formal contract or even payment to qualify as work, though it also said volunteer work in accordance with the Volunteer Service Act does not require a work permit.
In 2015, the Ministry of Labor issued another interpretation letter (104年11月3日勞動發管字第1040513517號函) that clarified the definition of volunteer work. There was a discussion here (thanks to @Feiren and Forward Taiwan).
In 2018, the MOL issued a new interpretation letter (勞動發管字第1070507378號函), which explains that the government now recognizes that some activities other than volunteer work should not be deemed work for purposes of Art. 42 to 44 of the Employment Service Act.
There are five categories:
- business activities (商務行為)
- academic internship or research activities (課程實習或研修行為)
- “supportive services” (輔助性服務行為 – basically volunteer work)
- “friendly” activities (一般聯誼行為)
- other activities that are not performed for the purpose of providing labor to any local entity and do not negatively affect the employment opportunities of citizens (其他非為境內任何人提供勞務為目的，且無妨礙本國人就業機會之行為)
There are examples given for each category, followed by criteria for determining whether or not an activity qualifies. The main theme is that these activities should not affect the local labor market. Another recurring theme is to avoid money changing hands, though this does not apply in all cases.
Some of the activities are only legal if you have a work permit (i.e. if you have a work permit for your regular job, you do not need an extra permit to do certain other things, but if you are a tourist you cannnot do those things).
Many people reading this will be interested in what the letter says about online activities, so here it is in full (item 3 in the fifth category).
The example given of permissible online activity is selling or auctioning goods, but this does not include the “provision of labor” (提供勞務), and the examples of provision of labor given here are massage service and language teaching. There is also a caveat about not violating the purpose of one’s visa (specifically with reference to the Social Order Maintenance Act, which is largely concerned with sex and violence), repeating the prohibition on “provision of labor”.
It should be noted that some people – mainly foreign spouses and permanent residents – were already and remain exempt from the requirement for a work permit, as long as they follow the proper procedures (discussed in other threads).