Global Mobility Tax: What do You Need to Know

Sending employees overseas opens doors to new markets, talent, and global collaboration. But it also opens up a complex web of international tax exposure that many companies underestimate — until it’s too late.

The good news? Managing tax risk in a globally mobile workforce doesn’t have to be painful — as long as you understand the terrain and stay proactive.

What Is Global Mobility Tax?

Let’s clear this up: Global Mobility Tax is not one global tax. It’s the tangled network of tax rules, compliance thresholds, and liabilities that apply when your employees work across borders.

You might face obligations related to:

• Payroll tax

• Social security contributions

• Permanent establishment (PE) risk

• Income tax residency

• Equity compensation

• Benefits-in-kind

• Even VAT exposure in some countries

Put simply: send an employee abroad, and multiple tax authorities may suddenly become very interested in what you’re doing.

The Real Tax Risks of Global Mobility

Global mobility tax exposure isn’t just about employee income — it’s about your company’s entire footprint in another country.

1. Permanent Establishment (PE)

If an employee works from a regular location, signs contracts, or makes key decisions while abroad, you may create a taxable corporate presence in that country.

What to watch for:

• Fixed addresses (even lockers or coworking desks)

• Local client meetings or contracts

• Day-count thresholds (often 183 days, but varies)

2. Double Taxation

Without a tax treaty in place, employees might face income tax in both home and host countries.

3. Residency-Based Taxation

Most countries use a 183-day rule to determine tax residency — but there are exceptions:

• Switzerland: 90 days

• South Africa: 330 days absence required to avoid tax

• USA: Taxes based on citizenship, not just residency

4. Social Security

Fail to get a Certificate of Coverage, and you or your employee could pay into two systems — unnecessarily.

5. VAT, Equity, and Benefits

Some countries treat personnel movement as taxable, including:

• VAT on intercompany recharges (e.g., Italy)

• Employee stock options taxed differently across borders

• Some benefits taxed in one country, ignored in another

📋 Global Mobility Compliance Rules for HR

HR and Global Mobility teams carry a heavy compliance burden — often without the tools or clarity to track risk in real time.

Here’s what your team should be doing:

✅ Monitor day counts

Use automation to track 90-day and 183-day thresholds across jurisdictions.

✅ Track activity — not just location

PE risk depends on what employees are doing, not just how long they’re abroad.

✅ Factor in personal ties

Residency decisions consider housing, family, and community ties.

✅ Maintain documentation

Digital + physical records = audit protection. Don’t rely on memory.

✅ Assume global taxation for US citizens

Citizenship-based taxation is the rule for Americans — even if they haven’t lived in the U.S. for years.

✅ Know the outliers

E.g., South Africa’s 330-day exemption rule, or Switzerland’s 90-day tax trigger.

🎙️ Why Listening to Expats Matters More Than Ever

At Advanced Client Metrics, we don’t file tax returns — but we work closely with global tax firms who do. Through our Voice of Customer (VoC) programs, we speak directly with expatriate taxpayers and the employers who depend on tax providers to deliver clarity and confidence.

Our call centers speak with millions of tax clients every year, across every continent and tax regime. What we hear isn’t just about compliance — it’s about trust, responsiveness, and the emotional toll of uncertainty.

When expats feel unsupported or blindsided by local tax rules, your firm’s reputation is on the line. That’s why our insights — gathered in real-time, not after the fact — help tax firms and HR teams course-correct before minor frustrations become full-blown breakdowns.

Final Thought

Cross-border tax risk is real, but so is the opportunity to get it right. With the right tools, partners, and feedback loops in place, global mobility can be a source of growth — not exposure.

If you’re ready to stop guessing and start listening to the people who matter most — the expats themselves — we’re here to help. info@advancedclientmetrics.com