How close are you to the 40% telework limit?
AdminLanding Editorial
Two different limits govern frontalier telework: 40% for tax (applying to pay since 01/01/2023), strictly below 50% for social security (since 01/07/2023). Project your year in ten seconds — free — then track the days that actually count.
Telework day counter — free
Your typical week, extrapolated to a full year, against both limits.
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.
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Net Frontalier converts your Swiss gross to French net with the current rates. See the cross-border hub
The two thresholds, side by side
| Tax — 40% | Social security — 49.9% | |
|---|---|---|
| The limit | Up to 40% of working time per calendar year | Below 25%: Swiss, ordinary A1 procedure · 25% to strictly below 50%: Swiss only with the A1 · 50% and more: French |
| Legal instrument | Geneva and the cantons outside the 1983 agreement: avenant to the 1966 FR-CH tax convention (décret n° 2025-838) · the eight 1983-agreement cantons: FR-CH amicable agreement of 22/12/2022 | EU/EFTA multilateral framework agreement + art. 16, Reg. (EC) 883/2004 |
| Since | In force 24/07/2025, applies to pay from 01/01/2023 | 01/07/2023 |
| Staying under it | Geneva and the other source-taxing cantons: the pay stays taxable in Switzerland · the eight 1983-agreement cantons: taxed in France, the frontalier status is kept | Below 25%: Swiss affiliation; the ordinary A1 procedure still applies (OFAS). From 25%: French legislation unless the employer requested and obtained an A1 (one employer or all in Switzerland, employees only, 3 years at most, renewable) |
| 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 · ge.ch — Accords applicables au télétravail (personnes frontalières), maj 23/04/2026 · Décret n° 2025-838 du 21/08/2025 (Légifrance — texte de l’avenant) · impots.gouv.fr — Accord amiable franco-suisse du 22/12/2022 (télétravail des frontaliers de l'accord du 11 avril 1983) · ne.ch — Frontaliers (conditions du statut ; à défaut, impôt prélevé à la source) — verified 30/09/2026 | Sources: CLEISS — Accord-cadre télétravail transfrontalier (07/2023) · OFAS/BSV (admin.ch) — Télétravail — verified 06/09/2026 |
Two different thresholds — not one rule
The 40% rule is about tax
What the 40% line means depends on the canton of work. Geneva and the other cantons outside the 1983 agreement: up to 40% of the calendar year's working time teleworked from France, the pay stays taxable in Switzerland (avenant in force 24/07/2025, applied to pay from 01/01/2023); above, every telework day from the first and every mission day becomes taxable in France. The eight cantons of the agreement of 11 April 1983: the pay is taxable in France; up to 40% the frontalier status is kept (amicable agreement of 22/12/2022); above, the employer withholds Swiss source tax.
« 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 — Genève et cantons hors accord de 1983) ; « dans la limite de 40 % du temps de travail par année civile sans remise en cause du régime dérogatoire « frontalier » prévu par l'accord précité » (accord amiable du 22/12/2022 — cantons de l'accord de 1983)
Sources: SIF (admin.ch) — Entrée en vigueur de l'avenant FR-CH · ge.ch — Accords applicables au télétravail (personnes frontalières), maj 23/04/2026 · Décret n° 2025-838 du 21/08/2025 (Légifrance — texte de l’avenant) · impots.gouv.fr — Accord amiable franco-suisse du 22/12/2022 (télétravail des frontaliers de l'accord du 11 avril 1983) · ne.ch — Frontaliers (conditions du statut ; à défaut, impôt prélevé à la source) — verified 30/09/2026
The 49.9% limit is about social security
Below 25% of working time teleworked from France: Swiss social security; the ordinary A1 procedure still applies (the competent institution of the state of residence decides — OFAS). From 25% to below 50%: FRENCH social security, unless your employer requested and obtained an A1 under the framework agreement (in force 01/07/2023; one employer or all employers in Switzerland; employees only; 3 years at most, renewable). 50% or more: French social security. 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) ; « La durée maximale de cette dérogation est de 3 ans, sachant que des prolongations pourront être accordées après une nouvelle demande. » ; « Si vous avez plusieurs employeurs, ces derniers doivent tous être établis dans le même État. » (CLEISS, Télétravail transfrontalier en Europe, lu le 30/09/2026)
Sources: CLEISS — Accord-cadre télétravail transfrontalier (07/2023) · OFAS/BSV (admin.ch) — Télétravail — verified 06/09/2026
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. Geneva and the other cantons outside the 1983 agreement: beyond 10 days only the EXCESS mission days become taxable in France (ge.ch, 19/05/2026). The eight cantons of the 1983 agreement: the 10-day limit is a condition of the frontalier status (ne.ch).
« pour autant que leur durée cumulée n'excède pas 10 jours par année » (décret 2025-838) ; « au maximum 10 jours de missions temporaires par an, en France ou dans un autre État » (ge.ch)
Sources: impots.gouv.fr — Accord amiable franco-suisse du 22/12/2022, § 3 (missions dans l'État de résidence ou un État tiers, 10 jours par année au plus) · ne.ch — Frontaliers (missions temporaires 10 jours au maximum, dans la limite des 40 % : condition du statut) · Décret n° 2025-838 du 21/08/2025 (Légifrance — protocole additionnel) · ge.ch — Accords applicables au télétravail (missions temporaires ≤ 10 jours), maj 23/04/2026 · ge.ch — Règles pour les missions temporaires à l'étranger (au-delà de 10 jours : seul l'excédent est imposable en France ; journées entières), maj 19/05/2026 — verified 30/09/2026
New frontalier? The droit d'option clock is already running
3 months from starting work in Switzerland, from moving to France if you already worked in Switzerland, or from the grant of a Swiss pension (Swiss pensions only). The form, stamped by your CPAM, must REACH the competent Swiss authority within the 3 months. Silence ⇒ automatic LAMal affiliation. The option is exercised once and is irrevocable; a new option opens only on resuming work in Switzerland (e.g. after a period of unemployment), moving to France, or retiring on Swiss pensions only. 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 · Formulaire « Choix du système d'assurance-maladie », version janvier 2024 (ameli.fr), p.1 et p.3 · ge.ch — Droit d'option pour les frontaliers résidant en France (maj 05/05/2026) · Code de la sécurité sociale, art. L. 380-3-1 (I et III — accord du 21 juin 1999) · OFSP — Assurance-maladie : Travailleurs frontaliers en Suisse (lu le 30/09/2026) · Règlement (CE) 883/2004, art. 2 §1, art. 11 §3 a) et art. 31 (CLEISS, texte consolidé) — verified 30/09/2026
Canton-specific consequences are never computed here — check the official references: ameli.fr · CLEISS · OFAS/BSV
Quick answer
A frontalier living in France and working in Switzerland faces two distinct telework limits. Tax — it depends on the canton of work: in Geneva and the other cantons outside the 1983 agreement, up to 40% of the calendar year's working time teleworked from France keeps the pay taxable in Switzerland, under the avenant to the 1966 FR-CH tax convention (in force 24/07/2025, applying to pay from 01/01/2023), and above it every telework day from the first and every mission day becomes taxable in France; in the eight cantons of the 1983 agreement the pay is taxed in France and telework up to 40% keeps the frontalier status (amicable agreement of 22/12/2022) — above it the employer withholds Swiss source tax. Temporary mission days count into the allowance only up to 10 cumulative 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. Below 25% Swiss legislation applies (the ordinary A1 procedure still applies); from 25% it is French legislation unless the employer obtained that A1. 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.
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?
Why 49.9% — and how is it different from the 40% rule?
Do mission days count as telework?
Does the tracker give tax advice?
Is it 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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The estimate is free. Your real days decide.
Log your Swiss, telework and mission days month by month, watch both thresholds with your remaining budget, and keep the droit d'option deadline in sight — free with an account. The AdminLanding membership adds the employer-co-signed presence attestation and the leaver attestation (€6 a month, renewed automatically every month; cancel any time from your account, effective at the end of the current monthly period. Employer co-signature: 2 signature credits, €1.50 per signer, not included).
Track my real days — free with an accountEU-hosted • Avenant FR-CH (décret 2025-838) • EU/EFTA framework agreement (art. 16, Reg. 883/2004)
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