I'm a Taiwan assignee spending 100 days in mainland China — is my Taiwan-paid salary taxable there?
Yes, most likely. Once you exceed 90 days in mainland China within a tax year, the 90-day exemption no longer shields you: employment income for work performed in China becomes taxable there, even if it's paid by your Taiwan employer into a Taiwan bank account. At 100 days, you're past the line.
The 90-day / 183-day rules
| Situation | Tax treatment of China workdays |
|---|---|
| In China ≤ 90 days in the tax year | Salary paid by overseas employer and not borne by a China entity: exempt |
| In China > 90 days but < 183 days | China workday portion taxable in China, regardless of who pays |
| In China ≥ 183 days | You may become a China tax resident — worldwide income in scope |
The 90-day count is cumulative days of physical presence in the tax year (January 1 – December 31), not per trip.
Who pays doesn't decide — where you work does
This is the part both HR departments get wrong. The Taiwan HR says "we pay you, so Taiwan taxes it" and the mainland HR says "we don't pay you, so it's not our problem." Chinese tax law looks at where the services were performed. If you did the work while physically in Shanghai, that slice of salary is China-sourced — full stop.
What to do practically
Track your days meticulously (entry/exit stamps). Apportion salary by workdays in each jurisdiction, file the mainland annual settlement (March 1 – June 30) for the China portion, and claim a foreign tax credit on your Taiwan return for tax paid in China so the same income isn't taxed twice.
Worked example: apportioning 100 days
Suppose your annual salary is NT$3,000,000 and you worked 240 days total, 100 of them in mainland China. Roughly NT$1,250,000 (100/240) is attributable to China workdays and taxable in China. You file the mainland annual settlement on that portion, pay the IIT, then claim the foreign tax credit on your Taiwan return for the same income. Keep a simple spreadsheet: date, city, workday yes/no — it takes five minutes a week and saves hours at filing time.
Frequently asked questions
Does the 90-day rule reset each trip?
No — it's cumulative presence in the calendar tax year. Ten trips of 10 days = 100 days.
What if my employer bears the cost through a mainland subsidiary?
Then even under 90 days the exemption generally doesn't apply — salary borne by a China establishment is taxable from day one.
Do weekends and holidays in China count?
Yes — physical presence counts all calendar days, not just workdays. But the taxable apportionment is typically done on workdays.
Sources
- https://www.pwc.tw/zh/news/press-release/press-20221117.html
- PRC Individual Income Tax Law Art. 1; Caishui [2019] No. 35 — 90-day rule for non-resident individuals