The 1983 agreement: why you are taxed in Switzerland in Geneva and in France in the canton of Vaud

Two French cross-border workers, same salary, same 40-minute commute. One works in Geneva: tax is withheld on the Swiss payslip. The other works in Nyon, in the canton of Vaud: they pay no tax in Switzerland and declare everything in France. The difference comes from a 1983 text — and it can amount to several thousand francs a year, in either direction.

1. An agreement signed in 1983, eight cantons concerned

The agreement of 11 April 1983 between Switzerland and France governs the taxation of cross-border workers' remuneration. Its principle is simple: salary is taxed in the State of residence, not in the one where the work is performed. For a French resident, that means taxation in France.

The agreement was not signed by all cantons, however. It covers eight cantons:

In exchange for giving up the right to tax, France pays the eight cantons a financial compensation of 4.5 % of the gross payroll of the workers concerned. The agreement is therefore not a gift: it is a trade.

2. Geneva: the opposite regime, and a payment in the other direction

Geneva never joined the 1983 agreement. The canton taxes cross-border workers at source, directly on the payslip, on a scale that depends on family situation (A, B, C or H).

Geneva, for its part, pays back 3.5 % of the gross payroll of its cross-border workers to the neighbouring French departments — Haute-Savoie and Ain — under an earlier agreement dating from 1973. These sums fund infrastructure and public services on the French side. This is the well-known "Geneva financial compensation", which amounts to hundreds of millions of francs each year.

3. The certificate of tax residence: the document that triggers everything

In the eight cantons of the agreement, exemption from Swiss tax is not automatic. You must give your Swiss employer a certificate of tax residence stamped by the French tax office of your domicile, to be renewed every year.

Without that document, the employer is required to withhold Swiss tax at source. You then end up taxed twice — in Switzerland by withholding, in France by declaration — and recovering the Swiss tax wrongly withheld requires a refund procedure with deadlines to respect. It is the most common administrative mistake when starting a first job.

4. What the agreement does not change: social contributions

A crucial and often misunderstood point: the 1983 agreement concerns income tax only. It does not touch social security, which is governed by separate European rules.

In other words, whether you work in Geneva or in Lausanne, you contribute in Switzerland in the same way: OASI/DI/LEC, unemployment insurance, accident insurance, occupational pension. These deductions are identical and appear on your payslip in both cases. Only the "tax" line differs: present in Geneva, absent in the canton of Vaud.

5. What it changes in net terms: a single person's example

Take a single person without children, CHF 100,000 gross annual salary, resident in France, with identical Swiss social contributions in both scenarios.

2026 estimate. French tax calculated on salary after mandatory social contributions, converted at CHF 1 = EUR 1.09, after the 10 % standard deduction for professional expenses, using the French progressive brackets (0 %, 11 %, 30 %, 41 %). Bracket thresholds are indexed annually. The Geneva withholding rate is an estimate for scale A0.

For a well-paid single person, the Geneva regime is therefore more advantageous — about CHF 365 more per month in this example. The reason is structural: the French scale reaches the 30 % bracket, then the 41 % one, at income levels where the average rate of Geneva withholding tax remains lower.

6. Families: the French family quotient often reverses the calculation

The previous result does not generalise. The French system has a mechanism Switzerland does not know in this form: the family quotient. Household income is divided by a number of shares that increases with the number of children, which sharply lowers the average tax rate of a single-income household with children.

Concretely:

• Single, good salary → Geneva withholding tax is generally lighter.
• Single-income couple with two or three children → the French family quotient substantially narrows the gap, and can reverse it.
• Couple where both spouses work in Switzerland → in Geneva scale C ("double earner") applies and increases the deduction; in France both salaries add up in a progressive scale. The calculation must be done case by case.

Two important nuances on the French side: the family quotient benefit is capped per half-share, which limits the gain for high incomes; and all household income — including the spouse's French income — enters the calculation, which is not the case for Geneva withholding tax, which only knows the Swiss salary.

7. The four classic pitfalls

Returning home

Cross-border status under the agreement presupposes a regular return home. Someone who lodges in Switzerland during the week and only goes home at weekends falls outside the agreement: they become taxable in Switzerland. This point can be verified — and it is.

Working from home

A France–Switzerland agreement allows part of working time to be performed from France — up to 40 % of annual working time — without changing the tax regime of the salary. In parallel, a separate European framework agreement allows working from home up to 49.9 % of the time while remaining covered by Swiss social security, on request. The two ceilings are independent and evolving: check the version in force for the year concerned, and have your situation confirmed by your employer.

Changing canton mid-year

Moving from a Geneva employer to a Vaud employer — or the reverse — changes the tax regime mid-year. You then combine a period of withholding tax with a period of taxation in France. Plan your cash flow: French tax is not collected at the same rhythm as Swiss withholding.

Dual activity

A job in Geneva and a second one in the canton of Vaud, or self-employment in France, require each source to be treated separately. This is where a filing error costs the most.

8. Health insurance: a choice independent of the tax regime

Whatever your canton of work, you have a right of option for health insurance, to be exercised within three months of starting work: stay in the Swiss system (LAMal) or join the French system (cross-border CMU). This choice is in principle final.

Its financial consequences are significant and independent of the tax regime: LAMal is paid through individual premiums, whatever your income; the French CMU is paid through a contribution based on reference taxable income, in the order of 8 % after a deduction. For a high income and a small family, LAMal can be more advantageous; for a large family on a modest income, it is often the opposite. Do the maths before signing: reversing the choice is difficult.

Frequently asked questions

Which cantons are covered by the 1983 agreement?

Bern, Solothurn, Basel-Stadt, Basel-Landschaft, Vaud, Valais, Neuchâtel and Jura. A French resident working in one of these eight cantons is taxed in France on their Swiss salary. Geneva and the other cantons apply Swiss withholding tax.

Does a cross-border worker in the canton of Vaud pay tax in Switzerland?

Not on their salary, provided they give their employer a certificate of tax residence stamped by the French authorities each year. They do continue to pay all Swiss social contributions.

Is it better to work in Geneva or in the canton of Vaud?

On tax alone, a single person on a high income is generally better off in Geneva, whereas a single-income couple with children often benefits more from the French family quotient. The gross salary offered, commuting time and housing costs often weigh more than the tax gap.

What happens if I do not go home every day?

You lose cross-border status under the agreement and become taxable in Switzerland. The regime depends on your actual residence situation, not on your nationality or your permit.

Is the 4.5 % compensation deducted from my salary?

No. It is a flow between States: France pays 4.5 % of the gross payroll of cross-border workers to the cantons concerned. It does not appear on your payslip and does not reduce your net pay.

Do I have to declare my Swiss salary in France if I work in Geneva?

Yes. Even when taxed at source in Switzerland, the salary must be declared in France, which grants a tax credit under the double taxation treaty. The Swiss income therefore influences the rate applied to your other income, without being taxed twice.