Who this is for
HR, People, Reward and Global Mobility teams relocating an employee to France — from the United States or elsewhere — as an intra-company transfer, a posting or a local hire. It covers the company’s obligations and the employee’s personal tax position, and the decisions that have to be made before the start date because they cannot be fixed afterwards. If you are the employee, our guide for individuals is Foreign residents in France: optimising your personal taxation.
⚠ Disclaimer. General information, current at the date of publication. It is not advice for a specific assignment: individual circumstances, the France–US tax treaty and the France–US social security agreement change the answer. Speak to us before acting.
Contents
- Start here: three decisions to make before day one
- Which of the three situations are you in?
- The employee’s French tax position
- The impatriate regime: the lever most HR teams miss
- Social security: a separate system, a separate decision
- Relocating an employee to France: what lands on the employer, even without a French entity
- Equity: the item discovered too late
- A timeline HR can work to
- Five mistakes we see most often
Start here: three decisions to make before day one
Most of what goes wrong when relocating an employee to France traces back to a decision made — or not made — before day one. These three are worth escalating now: two of them are far cheaper to settle before the start date than after it, and one of them, the social security certificate, genuinely has to be applied for in advance.
| Decision | Why it belongs before the start date | Cost of leaving it |
|---|---|---|
| Assignment type — transfer, posting or local hire | Determines the immigration route, which social security system applies, and which entity is the employer | Re-papering an assignment mid-stream is expensive and sometimes impossible |
| How the impatriation bonus will be exempted | Two routes. Exemption at the actual amount requires the bonus to be stated distinctly — or to be determinable from objective criteria — in the contract, the corporate mandate, or a rider drawn up before the employee takes up the position. The flat 30% election is available even if nothing is in the contract, so the regime is not lost either way | Leaving it means the actual-amount route closes and you are left with the flat election, which is not always the better result. Either route is capped by the reference-salary condition below |
| Social security position | A certificate of coverage must be applied for in advance; it is not automatic and it is time-limited | Contributions paid in the wrong country, then a correction in both |
Everything else in this guide is straightforward to correct later. These three are the ones worth an hour of someone senior’s time now.
Which of the three situations are you in?
The tax and payroll consequences follow the structure, so name it first.
| Intra-company transfer | Posting / detachment | Local hire | |
|---|---|---|---|
| Employer of record | Usually the French entity | Stays the home-country employer | The French entity |
| Contract | French contract or addendum | Home contract continues | French contract |
| Immigration route | Talent Passport (“salarié en mission”) or ICT card, depending on which entity holds the contract — see the visa guide below | ICT card or the posted-worker route, with prior SIPSI notification | “Salarié” card or Talent Passport |
| Social security | Depends on whether a certificate of coverage is obtained | Home system, if a certificate is obtained | French system |
| Impatriate regime | Available if the conditions are met | Available if the conditions are met | Available if the conditions are met — including intra-group mobility on a local contract |
The immigration mechanics are covered in our companion guide, Getting a work visa in France: a guide for employees of US groups.
The employee’s French tax position
When does the employee become French tax resident?
France applies a residence test based on the employee’s home, main place of stay, professional activity and centre of economic interests — any one of which can be enough. An employee relocating with their family to work in France will normally become French tax resident from arrival.
Residence is a French domestic-law question first. The France–US tax treaty then resolves the cases where both countries claim the same person, using tie-breaker rules. The two tests are not the same, and an employee can pass one and not the other.
The arrival year is not a normal year
In the year of arrival the employee is generally taxed in France on worldwide income only from the date French residence begins, and on French-source income before it. That has three practical consequences for HR:
- Payroll data has to be split. The assignee’s preparer needs earnings allocated before and after the residence date, and a workday record for the period.
- The first French return is filed the year after arrival, so the employee has a long gap in which nothing appears to happen, followed by a return more complex than any they will file later.
- Withholding and final liability rarely match in year one. Set the expectation early, especially under an equalization policy.
What the employee still owes their home country
An American assignee does not stop filing in the US. US citizens and green-card holders file on worldwide income regardless of where they live, and may have foreign account and asset reporting on top. Double taxation is mitigated through the treaty and through the foreign earned income exclusion or foreign tax credit — but that relief is claimed on a return; it is not automatic. See FEIE vs foreign tax credit and FBAR reporting for Americans in France.
HR implication
An American assignee needs two returns prepared, and they need to be prepared consistently. Two unconnected providers reliably produce two positions that contradict each other.
The impatriate regime: the lever most HR teams miss
This is the single most valuable thing on this page, and the one with a deadline.
The impatriate regime (article 155 B of the French tax code) exempts part of the remuneration of employees recruited from abroad to work in France. It applies to people who were not French tax resident in the five calendar years before taking up the position, and who become French tax resident when they start. For positions taken up since 6 July 2016 it runs until 31 December of the eighth calendar year following the year the employee starts — so someone starting in 2026 can benefit through 2034.
What is exempt: the impatriation bonus — either at its actual amount, which requires it to be stated distinctly, or determinable from objective criteria, in the contract, the corporate mandate or a rider drawn up before the employee takes up the position; or, by election, a flat 30% of net taxable remuneration, which is available even where the contract says nothing about a bonus. Added to it is the share of pay relating to work performed abroad for the employer, within caps. Entitlement survives a change of role within the host company and a change of employer within the same group.
The condition that applies to both routes
Whichever route is used, the exemption is allowed only so far as the remuneration remaining taxable in France is at least equal to that paid for comparable duties in the same company — or, failing an internal comparator, in similar companies established in France. This is the reference salary, and it is the employer’s job to determine it, document the method and tell the employee. It is tested annually. In practice it is what limits the exemption on a package that is generous relative to local pay for the role.
Why HR should care, in employer terms
Tax equalization means the employee keeps the tax position they would have had at home: a hypothetical home-country tax is deducted from their pay, and the employer then pays the actual French (and, for Americans, US) tax on their behalf, whatever it comes to. The employee is neither better nor worse off for moving; the employer carries the difference. Under such a package the employer bears the employee’s French tax, so a regime that reduces it reduces your cost directly. Under a non-equalized package it materially improves the employee’s net at no cost to you. Either way it depends on paperwork you control, and that paperwork has to exist before the employee starts.
Raise impatriate eligibility at the offer stage rather than at the first tax return. Nothing is lost outright by waiting — the flat election remains — but by then you have given up the choice between the two routes, and you have costed the assignment without the saving.
Social security: a separate system, a separate decision
Social security does not follow the tax answer. For the France–US corridor it is governed by the social security (totalization) agreement, not by the tax treaty, and the two instruments do not define their terms the same way.
An employee sent temporarily from the US to France can generally remain in the US system for a limited period, provided a certificate of coverage is obtained from the US Social Security Administration before departure. Without one, French contributions are generally due — and French employer contributions are a materially larger share of payroll cost than US employer payroll taxes, which is why this line item, missed, blows an assignment budget rather than merely annoying the assignee.
The point almost every relocation policy misses
An employee exempted from French contributions under the agreement is also outside the French health insurance system. The US Social Security Administration states that you or your employer must arrange private health insurance before the exemption can apply. Budget for it, and put it in the assignment letter.
- It is an application, not a status. Somebody has to file it, and it expires.
- A1 forms are not the instrument here. A1 certificates apply within the EU, EEA and Switzerland. For the US corridor it is a certificate of coverage under the totalization agreement. Providers used to intra-EU mobility routinely conflate the two.
- In the other direction, a French employer sending someone to the US requests form SE-404-1 or SE-404-2 from the French sickness-insurance agency.
Relocating an employee to France: what lands on the employer, even without a French entity
Companies assume that with no French entity there are no French obligations. That is not reliably true. French income tax is collected at source, and the obligation can reach employers established outside France whose employees are taxable in France.
A simplified regime introduced by the 2023 Finance Act replaces withholding with instalments paid by the employee — but only for employers established in the EU, the EEA or a state with the required assistance agreements with France, and only for employees who are not affiliated to French social security and whose activity in France is occasional and not substantial. An employee living and working full-time in France will normally be affiliated to French social security and working in France substantially, which takes the employer straight back into the full withholding obligation. The simplification is far narrower than it looks.
Whether a US employer qualifies for the simplified regime at all depends on how the France–US treaty’s assistance provisions are read. Take advice before assuming either way.
Equity: the item discovered too late
If the assignee holds RSUs or options, relocation changes where the income is taxed. Broadly, equity income is sourced by reference to workdays over the vesting period, so an award granted in one country and vesting after relocation can be split between both. France also operates its own regimes for qualifying awards, with their own conditions.
Practical consequence: your equity administrator’s default reporting is very unlikely to reflect a mid-vest relocation. Flag mobile employees to whoever runs the plan before the next vest, not after.
A timeline HR can work to
| When | What | Owner |
|---|---|---|
| Offer stage | Confirm assignment type; check impatriate eligibility; decide which exemption route you are using and draft the contract to match | HR + tax adviser |
| Before start | Apply for the certificate of coverage; arrange private health cover; start the immigration route; confirm the employer’s French withholding position | HR + payroll |
| Before start | Cost projection, including French employer contributions if they apply | Reward + finance |
| Month 1 | Brief the assignee on the two-country filing position; confirm the residence date; open the workday record | HR + adviser |
| Ongoing | Maintain the workday record; flag equity vests; watch the certificate’s expiry | HR |
| Year after arrival | First French return; US return if applicable | Adviser |
| Departure year | Departure return; closing the social security file | Adviser |
Five mistakes we see most often
- Treating the tax answer as the social security answer. Two systems, two analyses, two applications.
- Leaving the impatriate regime until the first tax return. The flat election will usually still be available, but the choice between the two routes — and the chance to cost the assignment properly — is gone.
- Assuming no French entity means no French obligations.
- No workday record. It cannot be reconstructed reliably a year later, and both the arrival-year position and the equity sourcing depend on it.
- Two unconnected providers. A French adviser and a US adviser who never speak produce two defensible positions that contradict each other.
How Expand CPA can help
We handle the individual side of the corridor for HR and Global Mobility teams: eligibility reviews before the offer goes out, cost projections, French and US return preparation for the same employee, and a named contact for your mobility team rather than a relationship per assignee. Because we hold both French and US qualifications, the two positions are reconciled before they reach your assignee.
Frequently asked questions
Does our employee become French tax resident as soon as they arrive?
Usually, if they move with their household and work in France — but residence turns on a set of tests, and the treaty can override the domestic answer where both countries claim the same person.
Can we keep our assignee on US social security?
Often, for a limited period, with a certificate of coverage obtained from the US Social Security Administration before departure. It must be applied for, it expires, and private health insurance has to be in place for the exemption to apply.
Do we have to run French payroll withholding if we have no French entity?
Possibly. Obligations can arise for foreign employers with employees taxable in France. A narrower simplified regime exists for occasional, non-substantial activity in France by employees outside French social security — which is not the position of someone who has relocated.
When is the first French return due?
In the year following arrival, covering the arrival year from the date French residence began.
Does the impatriate regime apply to a local hire?
It can, including intra-group mobility on a local contract, if the conditions are met. To exempt the bonus at its actual amount it must be in the contract, the mandate or a rider drawn up before the employee starts; otherwise the flat 30% election is available instead.
What happens to unvested RSUs?
They are generally sourced across the vesting period by workdays, so an award can end up taxed partly in each country. Flag it to your plan administrator early.
Relocating an employee to France?
We will map the obligations on both sides before they become corrections. Our global mobility services for employers.
