You are only allowed to legally work as an English teacher in Taiwan if you meet the following basic requirements:
* You have a bachelor’s degree (or 2 year associate diploma with TEFL certification) * You are a native English speaker * You have a passport from Australia, Canada, Ireland, New Zealand, South Africa, the United Kingdom or the USA
If you plan on working at a public school (as in a normal 8 – 5 school with a wide range of classes beyond just English) or a University, you will require other credentials such as a teacher’s license. The majority of English teachers in Taiwan, however, work in cram schools and these are the basic requirements." http://www.teachenglishtaiwan.net/who-can-teach-english-in-taiwan/ 上面不是台灣官方網站,不過大致上跟我之前所知道的差不多