EY Switzerland’s mobility-tax alert reminds companies that the supplementary agreement to the Franco-Swiss double-tax treaty has been ratified and is now fully in force. From 1 January 2026 Swiss employers must report, for every employee resident in France, the exact number of telework days, nights spent in Switzerland and business-travel days abroad if the employee teleworks up to the 40 % threshold. The reporting data – names, gross salary, and telework percentages – will be transmitted to the Swiss Federal Tax Administration (ESTV) via the Swissdec ELM 5.3 wage file and automatically exchanged with French tax authorities in 2027 (based on 2026 data). Employers must also be ready to issue a new “leaver’s attestation” summarising telework metrics when an employee changes jobs mid-year. Operationally, HR and payroll teams need to: (1) verify that time-tracking systems can differentiate between telework in France and other locations, (2) update employment contracts or telework agreements to reflect the 40 % ceiling and 10-day business-travel carve-out, and (3) obtain or renew A1 social-security certificates via the ALPS portal to avoid unexpected French contributions if the 50 % EU social-security threshold is breached.
![France–Switzerland telework deal triggers new employer reporting from 1 January 2026]()
For organisations that also juggle visa or work-permit questions for cross-border staff, VisaHQ can lighten the administrative load. Through its Switzerland portal (https://www.visahq.com/switzerland/), the platform offers clear checklists, online application tools and real-time status tracking, helping HR departments secure the right travel documents while keeping employees mobile between home, Switzerland and third-country business trips.
Failure to comply could expose Swiss employers to retroactive French PAYE withholding, social-security charges and penalties – an unwelcome prospect for multinationals with large cross-border commuter populations around Geneva, Basel and the Jura arc. Early communication with employees about accurate self-reporting of work locations will be critical as the first data-collection year (2026) is already under way.
For organisations that also juggle visa or work-permit questions for cross-border staff, VisaHQ can lighten the administrative load. Through its Switzerland portal (https://www.visahq.com/switzerland/), the platform offers clear checklists, online application tools and real-time status tracking, helping HR departments secure the right travel documents while keeping employees mobile between home, Switzerland and third-country business trips.
Failure to comply could expose Swiss employers to retroactive French PAYE withholding, social-security charges and penalties – an unwelcome prospect for multinationals with large cross-border commuter populations around Geneva, Basel and the Jura arc. Early communication with employees about accurate self-reporting of work locations will be critical as the first data-collection year (2026) is already under way.
