French taxes for Americans: the foyer fiscal, social charges and your US return

Live in Paris and you'll file with two tax offices: the French public finance service (the impôts) and the IRS. French rates and social charges usually leave little US tax on a French salary, but the two systems don't line up neatly, and investment income is where Americans get caught.

The short version

• France taxes you on worldwide income once your tax domicile is in France: your home or main place of stay is here, you work here (beyond incidentally), or your main economic interests are here [1].
• France taxes the household (foyer fiscal), not the individual. Income is divided by a number of shares (parts): one per single adult, two for a married or PACS couple, plus half a share per child for the first two [2].
• Rates on 2025 income, taxed in 2026, run from 0% up to 45% above EUR 181,917 per share [2].
• Social charges on investment income total 18.6% in 2026, up from 17.2%, mostly CSG (10.6%), CRDS (0.5%) and a 7.5% solidarity levy [3].
• The US–France tax treaty dates from 1994, with protocols in 2004 and 2009 [4]. The totalization agreement has been in force since July 1, 1988 [6].

USD conversions use the Federal Reserve H.10 rate of October 30, 2026: EUR 1 = USD 1.1163.

When France considers you a tax resident

Under Article 4 B of the French tax code, you have your tax domicile in France if any one of these is true [1]:

1. Your home (foyer) or main place of stay is in France. For a family, the foyer is generally where your spouse and kids live.
2. You work in France, as an employee or self-employed, unless the work is only incidental.
3. The center of your economic interests is in France, such as your main investments or business.

If you meet any test, France taxes all your income wherever it comes from (Article 4 A) [1]. A tax treaty can override this when you also count as a resident of another country, which matters for people who keep a home in the US. The treaty's tie-breaker rules then decide.

Notice what's missing: there's no pure day count like the 183-day rule Americans hear about elsewhere. Move to Paris with a job and a lease, and you'll generally be treated as a French tax resident from your arrival.

The foyer fiscal and the family quotient

This is the part that feels most foreign. France doesn't tax you; it taxes your household. A married or PACS couple files one joint return by default, and the family's taxable income is divided by its number of parts under the quotient familial [2]:

The tax is worked out on one part, using the scale below, then multiplied back by the number of parts. Kids lower the bill, but the benefit is capped. The cap for a couple with one child is EUR 1,807 (about USD 2,020) [2].

The 2026 scale (2025 income)

Source: Service-Public, verified April 15, 2026 [2].

A rough example, before any credits or other adjustments: a married couple with EUR 80,000 (about USD 89,300) of taxable income has two parts, so EUR 40,000 per part. On one part, that's 11% of EUR 17,979 plus 30% of EUR 10,421, about EUR 5,100. Times two parts, about EUR 10,200 (about USD 11,400). Compare that with the US, where a joint return uses wider brackets but doesn't divide by family size. For the full calculation, use the official simulator; the scale is only one step [2].

Since 2019, France collects income tax at source: your employer withholds it from each paycheck at a rate the tax office sets from your last return. You still file a return each spring to square up.

Social charges: CSG, CRDS and friends

On top of income tax, France levies social charges. On a salary, they come out of your paycheck along with French Social Security contributions, so most employees never see them as a separate bill.

On investment income (interest, dividends, capital gains), they're charged on top of income tax. In 2026, the general rate is [3]:

The jump from 17.2% in 2025 came from a CSG increase in the social security financing law of December 30, 2025. Some products, including assurance vie (life insurance savings), stay at 17.2% [3].

There's an exemption from CSG and CRDS, leaving only the 7.5% levy, but it's written for people covered by the social security system of another European Economic Area country or Switzerland [3]. The US isn't on that list.

How the US treats them

Here's the gray area. The treaty itself says it doesn't apply to social security taxes [5], and whether CSG and CRDS count as creditable foreign income taxes on your US return, or as social taxes tied to the totalization agreement, has been argued over for years. The IRS's stance has shifted over time. If you have meaningful French investment income, this is squarely a question for a US expat tax preparer, who can check your situation and whether amended returns make sense.

And a heads-up: French funds and savings wrappers can trigger the US PFIC rules. See Assurance vie and PEA: US tax traps.

The treaty: who taxes what

The US–France income tax treaty was signed in 1994, and protocols in 2004 and 2009 updated it. The IRS publishes all of them with their technical explanations [4].

Like every US treaty, it lets the US keep taxing its citizens. What makes the French one unusual is that France shares the burden for Americans living here [5]:

• France gives a credit for US tax, but only up to what the US could charge a French resident who isn't an American, and it exempts certain US-source income of US citizens from French tax.
• The US then credits the French tax on income where the extra US tax arises only because you're a citizen, and it treats part of that income as French-source so the credit fits inside the foreign tax credit limit [5].

In practice, this matters for US dividends, interest, pensions and Social Security. Our guide to tax treaties and totalization agreements explains the saving clause.

The Social Security agreement

The US–France totalization agreement took effect on July 1, 1988 [6]:

• Sent by a US employer for five years or less? Under the general rule, you stay in US Social Security and skip French contributions [6]. Your employer requests a certificate of coverage. Without French contributions you can't get French public health benefits, so you'll need private or employer insurance [7].
• Hired locally in Paris? You pay into French Social Security.
• Self-employed and working only in France? You're covered by France [7].

Filing both returns

Your US return still comes due every year:

• Deadlines: living abroad on April 15 gets you an automatic extension to June 15, and Form 4868 pushes it to October 15. Interest on unpaid tax runs from April 15 [8].
• Foreign tax credit (Form 1116): most Americans with French salaries claim it. French rates plus social charges usually wipe out the US tax on that income.
• Foreign earned income exclusion (Form 2555): up to USD 130,000 for 2025 and USD 132,900 for 2026 [9].
• FBAR: FinCEN Form 114 if your foreign accounts top USD 10,000 at any time, due April 15 with an automatic extension to October 15 [10].
• Form 8938: for Americans abroad, more than USD 200,000 at year-end or USD 300,000 at any time if single, double that for joint filers [10].

The French return is filed online in the spring, with deadlines staggered by département in late spring. You'll declare your foreign accounts, including US ones, on Form 3916; see the French tax return: declaring foreign accounts.

A yearly rhythm

1. January–March: collect your French pay statements and US tax forms.
2. By April 15: pay any US tax due.
3. Spring: file your French return by your département's deadline.
4. By June 15: file your US return, or extend.
5. By October 15: FBAR and any extended US return.

Want to compare notes on two returns? Ask in our community group for Americans in France.

Sources

1. Légifrance: Code général des impôts, Articles 4 A and 4 B
2. Service-Public: Income tax scale and family quotient (verified April 15, 2026)
3. Service-Public: Social charges on investment and property income (verified June 30, 2026)
4. IRS: France tax treaty documents
5. US Treasury: Technical explanation of the 1994 US–France treaty
6. SSA: US international Social Security agreements
7. SSA: Agreement between the United States and France
8. IRS: US citizens and resident aliens abroad
9. IRS: Figuring the foreign earned income exclusion
10. IRS: Comparison of Form 8938 and FBAR requirements

Keep reading

• The French tax return: declaring foreign accounts
• Assurance vie and PEA: US tax traps
• Foreign earned income exclusion vs foreign tax credit
• FBAR: reporting your foreign bank accounts