Remote Work Tax Implications: When Your Employee Moves Abroad

Your Employee Just Moved to Portugal. Now What?

An engineer on your team emails you on a Monday: “I’m moving to Lisbon next month. I’ll keep the same hours and the same role. Nothing changes.” Everything changes. Their tax residency may shift. Your company may owe corporate tax in Portugal. Social security contributions may need to move from one country to another. And if nobody catches it for six months, unwinding the mess costs five to ten times what prevention would have.

To convert this analysis into execution, map choices on comparison pages, use how to choose an EOR as your buying checklist, and prioritize markets via remote jobs by country.

This isn’t a hypothetical. EOR providers report that 15–20% of internationally employed workers relocate to a different country at least once during their employment. The compliance implications depend on how long they stay, what they do, and which two countries are involved.

The Day Thresholds: 30, 90, 183

Three numbers govern most cross-border work situations. They’re not universal — each country applies them differently — but they’re the framework every tax advisor starts with.

30 days is the threshold several countries use for short-term business traveler exemptions. The UK, for example, doesn’t require PAYE withholding for employees of non-UK employers who spend fewer than 30 days working in the UK within a tax year, provided the employer has no UK entity. Germany has a similar short-term exemption under certain bilateral tax treaties. Below 30 days, you’re usually safe — but “usually” isn’t “always.” Check the specific treaty between the two countries involved.

90 days triggers social security considerations in many EU states and activates work permit requirements in several non-EU countries. In the EU, the A1 certificate (more on this below) becomes practically necessary once an employee crosses the 90-day mark in another member state. Outside Europe, 90 days is often the limit for business visitor visa exemptions — after which the employee needs a work permit, and you may need a local entity or EOR in that country.

183 days is the number that changes everything. Most bilateral tax treaties use the 183-day rule to determine tax residency. Spend more than 183 days in a country within a 12-month period (or tax year, depending on the treaty), and that country generally claims the right to tax your worldwide income. For the employer, 183 days almost always creates a permanent establishment risk and potential corporate tax obligations.

The catch: these thresholds interact with each other and with country-specific rules in ways that don’t always align neatly. An employee who spends 150 days in France still triggers French social security obligations if they’re performing “habitual activity” there. The 183-day rule is a ceiling, not the only trigger.

Permanent Establishment: The Corporate Tax Trap

Permanent establishment (PE) is the risk that keeps CFOs awake. When your employee’s presence in a foreign country creates a PE, your company owes corporate tax in that country — potentially on all profits attributable to the employee’s activities there.

PE triggers vary by treaty, but the common ones are:

Fixed place of business. If your employee has a home office in Spain that they use daily for your company’s work, Spain may argue that constitutes a fixed place of business. The OECD’s updated guidance has narrowed safe harbors for home offices, and countries like France and Germany are applying this aggressively.

Dependent agent. An employee who habitually negotiates or concludes contracts on your company’s behalf creates PE risk in virtually every jurisdiction. This catches sales leaders, account managers, and BD leads working remotely in countries where you have no entity. The 2024 OECD framework expansion — covering employees who play a “principal role” in negotiation even without signing authority — makes this wider than it used to be.

Service PE. Some treaties (particularly with developing countries) define PE based on the duration of services provided. If your consultant or engineer performs services in India for more than 90 days in any 12-month period, certain India-specific treaty provisions can create a PE regardless of whether there’s a fixed office.

The financial exposure is real. A PE assessment typically means corporate tax on attributable profits (20–30% in most jurisdictions), plus penalties for non-filing, plus interest on unpaid tax. For a company with $5M in revenue attributable to an employee’s activities in Germany, the exposure could be €750K–€1.5M before penalties.

Within the EU/EEA, social security coordination is governed by Regulation 883/2004. The core principle: an employee pays social security in one country only. The A1 certificate proves which country that is.

When an EOR employs someone in France and that person works temporarily in Germany, the French A1 certificate confirms the employee remains under French social security. Without it, Germany can demand social security contributions — and France won’t automatically refund what’s already been paid. You end up paying twice.

A1 certificates matter most in three scenarios:

Business travel. An EOR-employed consultant based in the Netherlands who visits clients in Belgium, Germany, and France needs an A1 certificate for each trip. In practice, many companies skip this for short trips. In theory, enforcement exists — Belgian authorities have been known to check A1 certificates at construction sites and business parks.

Multi-state workers. An employee who regularly works in two or more EU countries (for example, splitting time between a Berlin home and a Paris client site) needs an A1 issued by the country where they perform a “substantial part” of their activity — generally 25% or more. This determination is not always straightforward.

Posted workers. An employee sent by their employer to work temporarily in another EU state requires an A1 before the posting begins. The posting can last up to 24 months before social security must transfer to the host country.

Most EOR providers handle A1 certificates for planned postings but don’t proactively manage them for ad hoc travel. If your team travels frequently within the EU, ask your provider explicitly whether A1 issuance is included or requires a separate request.

Country-Specific Triggers That Catch People

United States. State-level tax obligations create complexity that doesn’t exist in most countries. An employee who works from New York for more than 14 days may owe New York state income tax — even if they’re employed by a company with no US nexus. Several states (New York, California, Massachusetts) have “convenience of the employer” rules that tax remote workers based on where the employer is located, not where the employee sits. These rules originally targeted domestic situations but increasingly affect international remote arrangements.

Germany. The Finanzamt (tax office) has shifted from passive to active enforcement of PE indicators for remote workers. An employee working from Germany who participates in contract negotiations — even via video call from their Berlin apartment — can create PE risk. The 183-day rule applies within a calendar year (not a rolling 12-month period), which means careful timing matters.

Singapore. Tax residency is determined by physical presence: 183 days or more in a calendar year. Short-term employment (60 days or fewer) is exempt from tax for most employees. Between 61 and 182 days, income is taxed at the higher of the flat non-resident rate (15%) or the progressive resident rate. The gap between “no tax” and “15% flat rate” at the 61-day mark catches companies that don’t track days precisely.

UAE. The UAE introduced corporate tax in June 2023 at 9% on profits above AED 375,000. For companies with remote workers in the UAE, the question is whether the employee’s activities create sufficient nexus. The UAE’s Free Zone regimes add complexity — different rules apply depending on whether the employee works from a Free Zone or mainland.

Australia. The ATO’s 2025 guidance expanded the definition of when a foreign company’s remote worker creates a taxable presence. Decision-making authority is the key indicator. An employee who approves expenditures, sets strategy, or manages teams from Australia can create PE even if the company has no Australian entity.

What to Do When an Employee Relocates

Step 1: Assess the timeline. A two-week workation is low-risk. A 90-day stint requires planning. A permanent relocation requires a structural change — new employment contract in the new country, either through your existing entity or an EOR provider.

Step 2: Run a PE assessment. What does the employee do? If they’re a software developer with no client-facing or contract-signing responsibilities, PE risk is lower. If they’re a sales director who negotiates deals, PE risk is immediate regardless of duration.

Step 3: Check social security implications. Within the EU, determine whether an A1 certificate applies. Outside the EU, check whether a bilateral social security agreement exists between the two countries. These agreements prevent double contributions but require proactive application — they don’t apply automatically.

Step 4: Restructure employment if needed. For permanent relocations, the employee needs to be employed in the new country. If you have an entity there, transfer them. If not, an EOR can onboard them in the new country, typically within 2–5 business days in most markets. The old employment relationship terminates, and a new one begins under local law.

Step 5: Don’t forget immigration. A tax analysis is useless if the employee doesn’t have the right to work in the new country. EU citizens moving within the EU generally have automatic work rights. Everyone else needs a work permit or visa, and the employer (or EOR) typically sponsors it.

The cost of proactive compliance — running the assessment, obtaining the certificates, restructuring employment — is a fraction of the cost of retroactive cleanup. A PE assessment runs $3,000–$10,000 depending on jurisdiction. A PE assessment after the tax authority has already opened an inquiry runs $30,000–$100,000 in advisory fees alone, before any tax or penalties.

To move from strategy to execution, use remote jobs by country and benchmark provider options in EOR comparisons.