# AI assumes Taiwan's 183-day tax-residency threshold uses a rolling 12-month window, or that leaving and re-entering Taiwan resets the day count, when calculating whether a foreigner qualifies for resident (progressive) tax rates

- **ID:** `policy/tax-residency-183-day-calendar-year`
- **Domain:** policy
- **Category:** administrative_barrier
- **Verification:** ai_generated
- **Fix Rate:** 75%

## Root Cause

Taiwan's National Taxation Bureau defines resident status by calendar 'taxable year' (1 January - 31 December): a foreigner is a tax resident only if their cumulative days of presence reach 183 within that single calendar year, counted from passport or NIA entry-exit stamps and not reset by leaving and re-entering. Someone whose stay spans a year-end boundary can rack up nearly a year of continuous presence while never reaching 183 days in either individual calendar year, and gets taxed at the non-resident flat rate (18% on Taiwan-source salary for 90-183 days present) both years instead of the progressive resident rates (5-40%).

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| any | active | — | — |

## Workarounds

1. **Track cumulative days physically present in Taiwan within the current calendar year using entry/exit stamps or the National Immigration Agency's Certificate of Entry and Exit Dates; below 183 days means non-resident flat withholding (18% on Taiwan-source salary for 90-183 days present, also 18% if under 90 days and paid by a Taiwan-registered entity), while reaching 183 triggers progressive resident rates (5-40%) and a resident tax filing the following May** (85% success)

## Dead Ends

- **Assume Taiwan's 183-day tax-residency threshold uses a rolling 12-month window (as some other countries do), so a foreigner living in Taiwan continuously across a calendar year-end is automatically a tax resident** — National Taxation Bureau of Taipei defines the threshold strictly per calendar 'taxable year': a foreigner is a resident only if they accumulate at least 183 days within that single calendar year (1 Jan - 31 Dec). Someone who, say, arrives in August and stays continuously into the following June can fall short of 183 days in both the first calendar year (~5 months) and the second (~6 months) despite never leaving the country, and is taxed as a non-resident for both years. (60% fail)
- **Tell a foreign worker that days spent in Taiwan across several separate trips in the same calendar year don't add up toward the 183-day threshold because each departure resets the count** — NTBT's official 'Computing Period of Stay' guidance states that when a foreigner enters and exits Taiwan multiple times within a taxable year, the period of residence is the total accumulated days across all stays, not reset by departure; days are counted from entry/exit stamps, excluding the arrival date and including the departure date. (50% fail)