How to prepare an international mobility file before a URSSAF audit.
Companies expanding internationally face particularly complex regulations. Between social security agreements, tax treaties, payroll rules, reporting obligations and country-specific requirements, a simple mistake can have serious financial consequences. Yet many companies only discover their anomalies during a URSSAF audit, an internal review, a tax inspection, or when opening a subsidiary abroad.
What is an international payroll audit?
An international payroll audit involves analysing all of a company's social practices regarding employees working abroad. The goal isn't just to check payslips: the audit also examines employee statuses, social contributions, reporting obligations, social protection, applicable international agreements, mobility-related taxation, and internal procedures.
Main areas examined
Employee status — checking whether the choice between secondment, expatriation, local contract or intra-group mobility is legally appropriate. Social contributions — applicable regime, bilateral agreements, European regulations, affiliations, risks of double contribution. Payroll — French and foreign payslips, Split Payroll, Shadow Payroll, benefits in kind, variable remuneration elements. Tax obligations — tax residence, tax treaties, withholding at source, reporting obligations. Internal procedures — HR processes, approval workflows, documentation, exchanges between group entities.
When should you carry out an audit?
There's no need to wait for an audit. We generally recommend one before any first international mobility, when expanding abroad, before hiring an expatriate employee, when reorganising, after an acquisition or merger, or every two to three years for companies with regular international activity.
Most frequently detected mistakes
Misclassification of employees, social contributions paid in the wrong country, incorrect application of international agreements, payslip errors, poorly determined tax residence, incomplete documentation, insufficiently formalised internal procedures. These anomalies can represent tens of thousands of euros.
The benefits of an audit
Identifying anomalies before an audit, reducing financial risks, harmonising practices, securing international payroll, improving internal procedures, and strengthening social and tax compliance — a genuine decision-support tool for senior management.
Conclusion
International payroll is an area where mistakes are often very costly and can remain invisible for years. Carrying out an audit helps detect anomalies, secure procedures and anticipate regulatory changes before they become problems for the company.