Cross-Border Tax Return 2026: Step by Step
You're a Geneva cross-border worker: your salary is taxed at source in Switzerland. Yet every spring you must also declare that income in France. No double taxation, don't worry — just a formality to get right. Here's the 2026 step-by-step.
Do I really have to declare my Swiss income in France?
Yes, it's mandatory, even though tax was already withheld in Geneva. As a French resident, you declare your worldwide income. In practice, your Swiss income goes on form 2047 (foreign-source income), then on your main return 2042.
How is double taxation avoided?
Through the tax-credit mechanism in the Franco-Swiss treaty (article 25A). For a Geneva cross-border worker, your Swiss income is added to your French tax base, then a tax credit equal to the French tax calculated on that same income is granted. The result: that income isn't taxed a second time in France — the credit neutralizes the tax.
What exchange rate should I use?
To convert your 2025 income earned in Swiss francs, the official rate to apply is 1 CHF = 1.07 €. Use it on your annual salary (as shown on your Swiss salary certificate) before reporting it on your return.
What are the 2026 dates?
Online filing opened on 10 April 2026 on impots.gouv.fr. Deadlines depend on your department: around 22 May, 29 May or 5 June 2026 depending on your zone. Check yours — a late filing means penalties.
Am I a quasi-resident, and is it worth it?
If at least 90% of your household income is taxed in Switzerland, you can request quasi-resident status (subsequent ordinary taxation, TOU). It lets you deduct real expenses (third pillar, professional costs, loan interest…), like a Swiss resident. Watch the strict deadline: before 31 March following the tax year, via the DRIS/TOU form. After that, it's lost for the year.
The forms to know
- 2042: your main return;
- 2047: your foreign-source (Swiss) income;
- 2042-C: any extras;
- quasi-resident side: DRIS/TOU for the request, then the Geneva taxation form.
In short
- Swiss income must be declared in France: mandatory (2042 + 2047).
- Double taxation avoided by the tax credit (= French tax, art. 25A).
- 2025 exchange rate: 1 CHF = 1.07 €.
- 2026 dates: opens 10 April, deadlines 22 May → 5 June by department.
- Quasi-resident: request before 31 March (TOU) if 90% of income is in Switzerland.
For the gross-to-net calculation and quasi-resident detail, see our cross-border tax guide.
Also read:
