Vamoz | The 183-Day Rule: Why Calendar Days Matter More Than Just Workdays

Why focusing only on workdays can be a costly mistake

As hybrid and remote work models evolve, more companies are embracing workations or temporary remote setups abroad. Many respond by placing a cap on the number of workdays employees can spend working from another country. That feels like a smart and straightforward rule — it’s about work, so count the days worked, right?

Not exactly.

When it comes to compliance, particularly with tax authorities, it’s the total number of calendar days — not just working days—that matters. And that’s where the 183-day rule becomes crucial.

Workdays vs. Calendar Days: The Crucial Difference

Let’s break it down:

Workdays are the days an employee actually performs work—whether it’s a 15-minute Zoom call or a full eight-hour day.
Calendar (presence) days include every single day someone spends in a foreign country, even if they’re on vacation, sick leave, or just passing through.

Why this matters:

While companies may use workdays to measure productivity or manage internal scheduling, regulators use presence days to determine tax obligations and legal status.

Example:

An employee flies to Spain for a three-month stay, works 40 days remotely, and takes the rest as personal time. Internally, it looks like just 40 workdays abroad. But in the eyes of tax authorities, 90 calendar days have been spent in the country — bringing them halfway to triggering tax residency under some local rules.

Why the Distinction Really Matters

The 183-day rule is a central component of many double tax treaties and local tax laws. It’s intended to prevent double taxation and define residency based on time spent in a country.

But here’s the nuance:

The timeframe used to calculate those 183 days can vary significantly:

Some treaties use the calendar year (January to December)
Others rely on a rolling 12-month period from the date of arrival
A few apply the local fiscal or tax year, which might differ from the calendar year entirely

This variation makes it even more important for companies to track presence accurately.

An employee might stay under 183 days in a calendar year, but still exceed the limit in a rolling 12-month window or local tax year — unknowingly triggering tax obligations.

That’s why relying on static spreadsheets or employee self-reporting isn’t enough.

What Companies Should Pay Attention To

To stay ahead of compliance risks, companies must go beyond tracking productivity. Instead, they should be tracking:

Exact location of employees on any given day
Total duration of each stay abroad — including weekends and holidays
Frequency of travel — especially repeat trips to the same country
Applicable 183-day timeframe for each destination

Failing to do this opens up exposure to several potential risks, including:

Income tax liability for the employee (and possibly the employer)
Social security contributions in the host country
Immigration violations if work is performed without proper authorization
Permanent establishment (PE) risk, where the company could unknowingly create a taxable presence in that country

The OECD’s Position

International guidance adds weight to this issue. According to the OECD:

“A day counts as present if a person is physically in a country – no matter how briefly.”

So even if an employee arrives at 11:00 PM on a Saturday and leaves early Sunday morning —that’s two days counted.

What this means in practice:

A long weekend abroad, even without logging into work, still chips away at the 183-day threshold. And for countries using rolling 12-month windows, that number can sneak up on you faster than expected.

What This Means for Your Policy

Here’s the bottom line:

Your internal policy may say “30 days abroad per year,” but does that mean 30 workdays or 30 total days? That small difference could have huge tax consequences.

A better strategy involves dual tracking:

Public-facing policy: Define a clear allowance in workdays (e.g. “30 workdays per year abroad”)
Back-end tracking: Monitor total calendar days in the background, while also accounting for the specific 183-day timeframe that applies in each country

Doing so allows companies to honor flexibility while staying compliant.

How Vamoz Supports You

This is exactly where Vamoz steps in.

We help simplify international work by giving you:

Full visibility into where employees are and for how long
Automated day tracking across different 183-day rule variations — calendar year, tax year, or rolling 12 months
Risk detection and alerts tailored to each country’s tax framework
A single platform for HR and compliance teams to manage international work without manual guesswork

With Vamoz, your HR team no longer needs to chase down travel calendars or cross-reference complex treaties. Everything is tracked, flagged, and centralized—so you can support flexibility without fear of non-compliance. Because “work from anywhere” should never become “risk everywhere.”

FAQ - International Remote Work & The 183-Day Rule

Do only workdays count under the 183-day rule, or all days abroad? All calendar days count — including weekends, holidays, and personal days. It’s about physical presence, not whether work was performed.
When does an employee become tax liable in a foreign country? If they spend 183 days or more in a country within a specific period, they may become tax resident there. The definition of that period depends on local rules or tax treaties.
How does the 183-day rule vary across different tax treaties? Some treaties apply it to the calendar year, others use the domestic tax year, and some follow a rolling 12-month period. Understanding which timeframe applies is key for compliance.
Which countries use a rolling 12-month period instead of a calendar year? Countries like Germany, France, and Switzerland may use rolling 12-month windows. Always refer to the applicable double tax treaty for the exact rules.
What are the risks of ignoring the 183-day rule? You risk triggering income tax liability, social security obligations, immigration violations, or even permanent establishment issues for the company. These can have serious financial and legal consequences.
Do employers need to track employee locations and durations abroad? Yes — precise tracking of where employees are and how long they stay is essential for legal and tax compliance. Without this data, risk management is nearly impossible.
How can presence days be tracked automatically? Tools like Vamoz automate the tracking of calendar days — regardless of whether they are workdays or not—and align the data with local tax rules and thresholds.
When does permanent establishment (PE) risk arise for the company? If an employee works regularly and materially from abroad, authorities may view this as creating a taxable business presence. This risk depends on the nature of the work and the host country’s rules.
What is the OECD’s stance on day counting? The OECD states that any physical presence, even for a short time, counts toward the 183-day total. Work does not need to be performed for the day to be counted.
How does Vamoz support HR in staying compliant with international tax rules? Vamoz provides automated tracking, alerts when employees near critical thresholds like the 183-day rule, and helps HR manage remote work safely across borders — without manual spreadsheets.

The 183-Day Rule: Why Calendar Days Matter More Than Just Workdays