How Much Tax Should Be Withheld?

"Non-residents" must be withheld at 18% when they got paid for "Salary Income".
(If the monthly paid amount is lower than 1.5 times the basic wage, the rate is 6%. The basic wage since 2023 is NTD26,400)

For example, you receive NTD30,000 monthly so you have to be withheld at 6% for each time.

In Chinese new year,maybe the employer gives you one month bonus in February. (You get paid for salary and bonus in February) You receive NTD60,000 totally in February, it's over NTD37,875 so you have to be withheld at 18%.