183-Day Rule

The 183-Day Rule is the primary safe harbor threshold in the OECD Model Tax Convention. It states that a worker's physical presence in a country exceeding 183 days within any 12-month rolling period triggers potential permanent establishment obligations for the employing company.

The Rolling 12-Month Calculation

The test applies to any consecutive 12-month period, not just January–December. This is the most common source of miscalculation.

Example:

• Worker present 100 days (Oct–Dec 2025) + 90 days (Jan–Mar 2026) = 190 days in a rolling 12-month window
• Despite never exceeding 183 days in a single calendar year → Safe harbor lost

The Three Risk Zones

What Days Count

Days that count toward 183:

• Full days physically present in the country
• Partial days (arrival/departure days count as full days in most jurisdictions)
• Weekends and holidays during a continuous work assignment

Days that typically do not count:

• Pure vacation days (no work performed)
• Transit days (no work, not overnight)
• Days working for genuinely independent clients (for multi-client contractors)

Country-Specific Thresholds

Not all countries follow the 183-day standard. Some apply domestic thresholds that override tax treaty provisions:

• Philippines: 180 days under domestic tax law (NIRC)
• Germany: 183 days, but home office creates additional PE risk under domestic rules
• Always verify the applicable bilateral tax treaty for each jurisdiction.

The 50% Rule (OECD 2025 Update)

Even within 183 days, PE risk may arise if a worker spends more than 50% of their working time at a fixed location for business reasons (not personal convenience).

Source: OECD Model Tax Convention on Income and Capital, 2025 Update, Article 5.