The public counter is free, needs no account, and stores nothing. The full tracker — month-by-month day log, both thresholds, remaining-day budget and droit d'option countdown — is part of AdminLanding's Cross-Border France-Switzerland pack: €29 one-time, no subscription. Creating an account is free.

How close are you to the 40% telework limit?

Last updated 4 August 2026AdminLanding Editorial

Since 01/01/2026, two different limits govern frontalier telework: 40% for tax, strictly below 50% for social security. Project your year in ten seconds — free — then track the days that actually count.

Use the free counter All frontalier tools

Telework day counter — free

Your typical week, extrapolated to a full year, against both limits.

Working days per week

Telework days per week (from France)

Mission days so far this year (optional)

Temporary missions in France or a third country. They count into the telework share only up to 10 days per year (décret 2025-838).

Enter your telework days per week to project your year against both limits.

Track your frontalier net salary too

Net Frontalier converts your Swiss gross to French net with the current rates. See the cross-border hub

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Quick answer

A frontalier living in France and working in Switzerland faces two distinct telework limits. Tax: up to 40% of annual working time teleworked from France keeps the pay taxable in the employer state, under the avenant to the 1966 FR-CH convention (in force 24/07/2025, applicable from 01/01/2026) — with temporary mission days counting into that allowance only up to a cumulative 10 days per year. Social security: under the EU/EFTA framework agreement (since 01/07/2023), telework strictly below 50% of total working time — displayed as 49.9% — can keep Swiss affiliation via an employer-side A1 request (art. 16, Regulation 883/2004); it is not automatic. The two limits come from different instruments and have different consequences, so both need watching: this page extrapolates your typical week; the in-app tracker counts your real recorded days.

The two thresholds, side by side

The frontalier tax and social-security telework thresholds compared: limit, legal basis, effect of staying under, mission days.
	Tax — 40%	Social security — 49.9%
The limit	Up to 40% of working time per calendar year	Strictly below 50% of total working time
Legal instrument	Avenant to the 1966 FR-CH tax convention (décret n° 2025-838)	EU/EFTA multilateral framework agreement + art. 16, Reg. (EC) 883/2004
Since	In force 24/07/2025, applies from 01/01/2026	01/07/2023
Staying under it	Telework pay stays taxable in the employer state (Switzerland)	Swiss social-security affiliation can be kept — via the employer-side A1 request, not automatically
Mission days	Count within the allowance only up to 10 cumulative days per year	Conditions: single employer state, salaried only, employer request + employee consent
Sources	Sources: SIF (admin.ch) — Entrée en vigueur de l'avenant FR-CH · Décret n° 2025-838 du 21/08/2025 (Légifrance — texte de l’avenant) — verified 04/08/2026	Sources: CLEISS — Accord-cadre télétravail transfrontalier (07/2023) · OFAS/BSV (admin.ch) — Télétravail — verified 04/08/2026

Two different thresholds — not one rule

The 40% rule is about tax

Up to 40% of annual working time teleworked from France keeps the pay taxable in the employer state. In force 24/07/2025, applies from 01/01/2026.

« dans la limite de 40 % du temps de travail par année civile […] les rémunérations afférentes au télétravail sont imposables dans l'État contractant où se situe l'employeur » (SIF / avenant)

Sources: SIF (admin.ch) — Entrée en vigueur de l'avenant FR-CH · Décret n° 2025-838 du 21/08/2025 (Légifrance — texte de l’avenant) — verified 04/08/2026

The 49.9% limit is about social security

Below 50% of total working time teleworked from France can keep Swiss social-security affiliation (framework agreement, since 01/07/2023) — requires the employer-side A1 procedure; not automatic. Distinct from the 40% TAX threshold.

« moins de 50 % du temps de travail total » — dérogation art. 16 du règlement (CE) n° 883/2004, document portable A1 requis (CLEISS)

Sources: CLEISS — Accord-cadre télétravail transfrontalier (07/2023) · OFAS/BSV (admin.ch) — Télétravail — verified 04/08/2026

Mission days: the 10-day sub-cap

Temporary mission days (in France or third countries) count as telework within the 40% only up to a cumulative 10 days per year.

« pour autant que leur durée cumulée n'excède pas 10 jours par année » (décret 2025-838)

Sources: Décret n° 2025-838 du 21/08/2025 (Légifrance — protocole additionnel) — verified 04/08/2026

New frontalier? The droit d'option clock is already running

3 months from starting Swiss employment (or taking French residence / first Swiss pension payment). Silence ⇒ automatic LAMal affiliation. One-time, irrevocable except on enumerated status changes. Compare the two health systems with the free LAMal vs CMU calculator, and find every frontalier tool on the France-Switzerland hub.

Sources: ameli.fr — Travailleur frontalier suisse (maj 30/04/2026) · CLEISS — FAQ droit d'option des frontaliers France-Suisse — verified 04/08/2026

Canton-specific consequences are never computed here — check the official references: ameli.fr · CLEISS · OFAS/BSV

Frequently Asked Questions

The 40% rule, the 49.9% limit, mission days, what the tracker does and doesn't do.

What is the 40% telework rule for frontaliers?

Under the avenant to the 1966 France-Switzerland tax convention, up to 40% of annual working time teleworked from France keeps the related pay taxable in the employer state (Switzerland). The avenant entered into force on 24/07/2025 and applies from 01/01/2026. Beyond the limit, the ordinary treaty rules apply to the telework days — which is why the share of your own recorded days is the number to watch. Sources: SIF (admin.ch) and décret n° 2025-838 (Légifrance).

Why 49.9% — and how is it different from the 40% rule?

It is a separate instrument entirely. Under the EU/EFTA multilateral framework agreement on cross-border telework (in effect since 01/07/2023, France and Switzerland both signatories), telework strictly below 50% of total working time can keep the Swiss social-security affiliation — via an employer-side A1 request under article 16 of Regulation (EC) 883/2004, so it is not automatic. It is conventionally displayed as 49.9%. Crossing 40% is a TAX question; reaching 50% is a SOCIAL-SECURITY question — two different limits, two different consequences. Sources: CLEISS and OFAS/BSV (admin.ch).

Do mission days count as telework?

Partly. Temporary mission days in France or a third country count within the telework allowance only while their cumulative duration stays at or under 10 days per year (protocole additionnel, décret n° 2025-838: "pour autant que leur durée cumulée n'excède pas 10 jours par année"). This counter therefore caps the mission days it adds to your telework share at 10; the in-app tracker logs them as their own category so the cap is visible, not silently absorbed.

Does the tracker give tax advice?

No. It tracks and surfaces facts: it counts the days you enter and shows the resulting share against the published thresholds, each with its primary source. What crossing a threshold means for your situation depends on your employment arrangements, your canton and the competent institutions — the tool routes you to the official sources (ameli.fr, CLEISS, OFAS, URSSAF) and, where a judgment call is needed, to a qualified professional. It never recommends a course of action.

Is it free?

This page is free, needs no account, and stores nothing you type. The full tracker — the month-by-month day log, both thresholds side by side, the remaining-day budget and the droit d'option countdown — is part of AdminLanding's Cross-Border France-Switzerland pack: €29 one-time, no subscription. Creating the account itself is free.

Important: AdminLanding is a technology platform, not a tax adviser, law firm or social-security institution. This counter extrapolates the figures you enter against the published treaty and statutory thresholds (avenant to the 1966 FR-CH convention, EU/EFTA framework agreement, décret n° 2025-838), for information purposes only — it is not tax, legal or social-security advice, and your actual position depends on your employment contract, your employer's A1 arrangements and the competent institutions. Verify with the official sources cited on this page (SIF, Légifrance, CLEISS, OFAS, ameli.fr, URSSAF) or a qualified professional before acting.

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EU-hosted • Avenant FR-CH (décret 2025-838) • EU/EFTA framework agreement (art. 16, Reg. 883/2004)