I’d say that highly depends on what exactly you’re planning to do.
The linked threads contains a link to a document stating the following:
On 2 September 2015, the Ministry convened a meeting of experts and concerned agencies to study whether the Employment Services Act applies to foreign nationals who work without consideration for their services. The experts and representatives of the concerned agencies took the view that that the purpose of the Employment Services Act is to protect the employment opportunities of Taiwanese citizens. However, the provision of supporting services 2 is not work
under the Employment Services Act if the following is true:
a. Provision of the supporting service does not impair employment opportunities for citizens;
b. The foreign national is making a voluntary contribution to society for a purpose in the public interest;
c. The foreigner’s purpose is not to receive payment; and
d. The supporting services are not rendered in exchange for a proportional payment
If your volunteer work falls into the category of cleaning up beaches and such, you should probably be fine. However, when you volunteer in an office or similar, someone could already argue that you’re taking away jobs from citizens and thus it wouldn’t count as volunteering in the sense that no work permit is required…
And there is this part:
The Volunteer Service Act covers volunteer work for government agencies, public institutions, foundations and registered public interest associations (NGOs). A foundation or association is required to file a written volunteer
service plan. Foreign nationals have been permitted to perform volunteer services under volunteer service plans without a work permit since 2005. Examples of organizations with volunteer service programs include the Eden
Social Welfare Foundation and the Taiwan Foundation for Rare Disorders.
So it also depends on whom you volunteer for: “Volunteering” for a regular company / individuals, for example, also doesn’t seem to be covered. If it’s a officially registered NGO, chances are probably higher.
If you want to be on the safe side, better look into visas that allow work (e.g. work&travel if you qualify).
Of course, there is always the option of “flying under the radar” - but in the worst case, this can lead to deportation and a re-entry ban (although the chances of getting caught are rather low unless someone reports you - which could, however, happen in case you get into some kind of dispute with a colleague, landlord, …).
