what is the tax on my salary?

In the same tax year, the teacher must stay more then 183 days, then he/she can try to file the tax refund.

The first 183 days, it’ll be 18% of your salary, after 183 days, it’ll be 5-6% of your salary.

e.g. if you come in September, then from Sep-Dec, your salary  will be deducted 18% ; if you come before July, then you will still be deducted 18% between July-Dec but can always get it refunded the next year.

Even if you’re not in Taiwan that time, you can still have it done on line.