{
  "id": "policy/tax-residency-183-day-calendar-year",
  "signature": "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",
  "signature_zh": "",
  "regex": "(taiwan.*183 day|taiwan.*tax resident|taiwan.*non.resident.*tax|taiwan.*flat.*18%.*tax)",
  "domain": "policy",
  "category": "administrative_barrier",
  "subcategory": null,
  "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%).",
  "root_cause_type": "generic",
  "root_cause_zh": "",
  "versions": [
    {
      "version": "any",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "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",
      "why_fails": "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.",
      "fail_rate": 0.6,
      "condition": "Stay spans a calendar year-end without reaching 183 days in either single calendar year",
      "sources": [
        "https://www.ntbt.gov.tw/English/htmlList/bfc158abe6fe4e43b301e491263e7fee",
        "https://www.ntbt.gov.tw/english/multiplehtml/06922971ae7e48d18d2902dfa6ebfcea"
      ]
    },
    {
      "action": "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",
      "why_fails": "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.",
      "fail_rate": 0.5,
      "condition": "Multiple entries and exits within one calendar year",
      "sources": [
        "https://www.ntbt.gov.tw/english/multiplehtml/06922971ae7e48d18d2902dfa6ebfcea"
      ]
    }
  ],
  "workarounds": [
    {
      "action": "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",
      "success_rate": 0.85,
      "how": "",
      "condition": "General",
      "sources": [
        "https://www.ntbt.gov.tw/English/htmlList/d8fa239122dc4d14989884c1ded43df8"
      ]
    }
  ],
  "workarounds_zh": [],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": [
      "medical/health-insurance-six-month-clock/tw"
    ]
  },
  "official_doc_url": null,
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.65,
  "fix_success_rate": 0.75,
  "resolvable": "true",
  "first_seen": "2026-08-31",
  "last_confirmed": "2026-08-31",
  "last_updated": "2026-08-31",
  "evidence_count": 3,
  "tags": [],
  "locale": "en",
  "aliases": [
    "policy/tax-residency-183-day-calendar-year/tw"
  ]
}