10 days
Business trips
Up to 10 days of trips count within the 40%. Trips beyond 10 days are taxed in France.
Swiss employers French-resident staff2026 reporting
Your French-resident employee works 38% from home. Are you compliant?
Business trips count in the same calculation. Social security runs on a different line. And since 1 January 2026, you have to track all of it.
Count one employee's year
Illustrative. Assumes 220 working days and one day per trip.
40% = 88 days
Telework 84 daysTrips 8 days
Combined
92 days (42%)
Income tax line (40%)
4 days over the limit
Social security
Above 25%: A1 relevant
Where this employee sits on the percentage lines
Below 25%No A1 question
25–40%A1 relevant
40–49.9%France taxes
50%+Ordinary rules
Telework 38%
Telework plus trips (42%)
An employee lives in France and works for your Geneva office. She works from home 38% of the year. The French-Swiss tax ceiling is 40%. You are safe, right?
Not yet. Business trips count in the same calculation. Social security runs on a different line. And since 1 January 2026, you have to track all of it.
What changed on 1 January 2026
The amendment to the France-Switzerland double tax treaty applies from 1 January 2026. Switzerland's State Secretariat for International Finance confirms the date. Up to 40% of working time per calendar year, telework pay stays taxable in the employer's state.
The 40% figure is not new. swissinfo reported in October 2024 that Switzerland agreed a 40% limit with France and 25% with Italy. What is new in 2026 is your job as the employer.
The Canton of Geneva's tax administration is direct about it. Employers must track telework days and temporary missions for each employee domiciled in France. The first transmission is due in January 2027, covering 2026.
Four thresholds, four different consequences
Each line runs on its own. Passing one does not clear the others.
25%
Social security
Above this level, affiliation questions start. A telework A1 certificate becomes relevant.
40%
Income tax
Up to 40%, Swiss taxation holds. Above it, France taxes telework from the first day, plus all trip days.
49.9%
Social security
The multilateral framework covers 25% to 49.9% of telework. At 50% and above, ordinary rules apply.
The tax rules come from the Canton of Geneva's accords page. The social security lines come from Entreprise Romande, which covers the framework in force since 1 July 2023.
A worked example: 38% home office
This example is illustrative. It assumes 220 working days a year.
84
home days
+8
trip days
92
about 42%
At 38%, your employee works 84 days from home. She also takes eight business trips outside Switzerland, each counted as one day. That makes 92 days, or about 42% of her working time.
The 40% limit is 88 days. She is four days over. Under the Geneva rules, Switzerland taxes telework and trips up to the limit. France taxes the trips beyond it.
Social security is a separate test. At 38%, she sits above the 25% line. You need an A1 certificate to keep her in the Swiss system.
Look at your own policy. "Two days a week from home" sits at exactly 40% before a single trip. The legal test is annual, so the policy needs actual counting.
What you have to report
The rate
You calculate the telework rate from your own records. In Geneva, it goes on the liste récapitulative, on paper or through ELM or ISeL. It does not go on the salary certificate. Other cantons can differ, so check yours.
Special cases
For a part-time employee with several employers, you declare only the days worked for you. For a mid-year change of residence, you declare only the rate for the period spent in France.
Social security
You request the A1 certificate through ALPS, the Applicable Legislation Platform Switzerland. France validates the request first. According to Entreprise Romande, certificates can be issued retroactively for three months at most. Waiting is expensive.
Why your numbers will not match
Each team holds a different piece, and every one of them keeps a count. Few of the counts agree.
HR
owns the telework policy
Travel
owns the trip data
Payroll
owns the reporting channel
Social security
owns the A1 certificates
84%
of mobility teams lack visibility into where employees work.
Topia AI Inflection Point report
If HR records one number and payroll reports another, you cannot defend either. Once you transmit, the reported rate becomes your reference point for every later question.
What counting properly looks like
You need one day count, one owner and one reconciliation before you transmit. Start with five steps:
- Step 1
Map your population. List every employee who lives in France and works for a Swiss entity. Flag the ones close to the 10-day, 25%, 40% and 49.9% lines.
- Step 2
Count every working day by country. Record remote days, trips, training and client visits in one place. Adjust for public holidays and part-time schedules.
- Step 3
Turn travel approval into a tax control. Check the running trip count before a manager signs off. Topia Horizon's Pre-Travel Assessment screens tax withholding, social security and permanent establishment before a trip is booked.
- Step 4
Keep a location record behind the number. Monaeo, a Topia company, tracks where your people work and evaluates tax exposure. That gives you evidence for the rate you report.
- Step 5
Reconcile before January. Compare HR, payroll, travel and compensation records for each employee. Fix every mismatch before you transmit.
The 2026 count is already running. About 11 weeks remain, so start the reconciliation now.
Get the checklist
We built a checklist for the year-end count. It covers who to map, which lines to watch and what to reconcile. It also has an owner table for payroll, HR, travel, compensation and social security.
See how Topia and Monaeo fit your count.
This article is general information, not tax or legal advice. Confirm your position with a qualified adviser.