Cross-Border HR Compliance
The 2026–27 Readiness Series for frontaliers and cross-border employees
The trigger is simple: from calendar year 2026, Swiss employers must track the days worked outside Switzerland by French-resident employees and transmit the relevant telework data to the tax authorities from January 2027. In practice, this means that remote work, business travel, payroll reporting, social security affiliation and individual tax status will all depend on the quality of the employer’s processes for counting these days.
For organisations with French-resident employees — particularly in Geneva, Vaud, Neuchâtel, Jura and Basel — the compliance question is no longer whether cross-border work is permitted. It is whether the company can provide evidence, employee by employee and year by year, that the applicable thresholds have been monitored, documented and correctly reported.
Why 2026 matters
The French-Swiss framework has moved from temporary tolerance to permanent control. The Avenant to the France-Switzerland double tax treaty is applicable from 1 January 2026, and the French-Swiss mutual agreement of 29 April 2026 further clarifies the operational framework. Under this regime, a French-resident employee may work outside Switzerland for up to 40% of annual working time without changing the primary Swiss taxation outcome, provided that specific conditions are met.
The point that many employers underestimate is that business travel is part of the same fiscal equation. Temporary missions, including business trips, training, client meetings and other professional activities performed in France or in a third country, are included in the annual calculation, within a specific sub-limit of 10 days per year. This means that an employee who rarely works from home may nevertheless create French tax exposure through frequent business travel.
The second practical shift is data transmission. From January 2027, employers must be ready to report the telework rate for the 2026 calendar year, and Swiss authorities have indicated that the relevant reporting processes will be adapted for this purpose. Payroll will therefore become more than a payment function. It will become the official compliance record for cross-border work.
The compliance map
The 2026 framework requires employers to manage several thresholds at the same time. These thresholds do not replace one another. They operate independently, and each one leads to a different compliance consequence.
|
Threshold |
Area |
Practical consequence |
|---|---|---|
|
10 days |
Business travel |
Temporary missions are included in the tax calculation and are subject to a specific annual sub-limit. |
|
25% |
Social security |
Above this level, a telework A1 certificate becomes relevant under the multilateral framework. |
|
40% |
Income tax |
The French-Swiss tax regime allows telework up to this annual ceiling, subject to the applicable conditions. |
|
49.9% |
Social security |
The multilateral telework framework applies between 25% and 49.9% where the conditions are met. |
|
90% |
Individual tax status |
The Swiss quasi-resident analysis may be affected where part of the employee’s income becomes taxable outside Switzerland. |
The operational difficulty is that these thresholds are not owned by a single function. Payroll owns the reporting channel. HR owns the telework policy. Travel teams hold the business travel data. Compensation and benefits teams may hold equity and pension information. Social security specialists manage A1 certificates and determinations of applicable legislation. The 2026 framework requires these functions to work from the same dataset.
Payroll: the first compliance record
The priority is payroll because payroll is where the new transparency becomes visible. Employers will need to report a structured dataset to the tax authorities, including employee identification, compensation information and the relevant telework data for French-resident employees. The first transmission is expected in January 2027 for the 2026 calendar year.
This creates an immediate governance question. If HR records one number, payroll reports another, and travel systems a third, the organisation’s position will not be defensible. Employers should therefore build a single source of truth for remote work and business travel, with daily granularity and country-level accuracy.
The payroll challenge is not merely technical, but evidentiary. Once the data has been transmitted, it becomes the reference point for future questions from tax authorities, employees and internal stakeholders.
Social security: the A1 question
The second step addresses social security, where the 25% threshold remains a critical line. The multilateral telework framework applies to cross-border telework between 25% and 49.9% of working time, and the employer must request an A1 certificate through ALPS — Applicable Legislation Platform Switzerland — where the relevant conditions are met. Below 25%, the analysis is different, but employers may still need to initiate a determination of applicable legislation through the competent authorities, depending on the employee’s situation.
The practical issue is timing. Employers should not assume that retrospective regularisation will be available without limitation, particularly where hybrid arrangements have evolved informally and no determination on the applicable legislation or A1 documentation has been obtained in time. This makes early population mapping and threshold monitoring essential.
Frequent travellers require particular attention. An employee who combines French- residence telework with regular business travel in the EU or EEA may require a separate analysis, because occasional detachment and habitual multi-state activity do not follow the same operational logic. In this environment, an A1 certificate is no longer a technical formality. It is evidence that the employer has identified the correct social security jurisdiction.
Remote work and business travel
The third step brings the framework together by focusing on remote work and business travel. These are different working patterns, but for tax purposes they feed into the same annual calculation. The Swiss authorities' guidance guidance confirms that temporary missions are included in the telework-related computation, within the 10-day annual limit, and that exceeding the relevant thresholds can lead to taxation in France for the relevant days.
This is where many existing HR policies are too imprecise. A policy allowing “two days per week” may look compliant, but the legal test is annual and requires actual counting of the days involved. Public holidays, part-time work, travel days, training days, equity vesting periods and changes in work pattern all affect the practical result.
Business travel is the hidden trigger. A senior executive who works mostly in Geneva but regularly attends meetings in Paris, London or Frankfurt may create a tax and social security issue even without a high level of home office working. The compliance framework therefore requires employers to treat travel approval as a fiscal and social security control point, not only as a mobility or expense-management process.
What employers should do now
The 2026 compliance year is already running. Employers should not wait until January 2027 to reconcile the data. They should map their French-resident population now, identify the employees close to the 10-day, 25%, 40% and 49.9% thresholds, and test whether payroll, HR, travel and compensation systems produce the same answer.
The target operating model should be simple: one day-count, one employee record, one compliance owner, and one annual reconciliation process before transmission. This is particularly important for organisations with equity plans, frequent travellers, senior executives, part-time arrangements, or employees whose quasi-resident position depends on remaining within the Swiss-source income threshold.
The organisations that act early will enter 2027 with an auditable position. The organisations that wait will still transmit data — but they may not control the story that the data tells.
Explore our deep dives
Over the coming weeks, we will release several deep dives.
