The Contrat à Durée Indéterminée (CDI), or open-ended employment contract, is the default and most prevalent form of employment relationship in France. Under French labour law, any contract that does not explicitly state a fixed term is presumed to be a CDI. There is no expiry date, and both parties are bound until one initiates termination through a legally defined procedure.
Because the CDI is treated as the standard, employers face substantive obligations when ending the relationship. Dismissal requires a genuine and serious cause (cause réelle et sérieuse), advance notice, a formal procedure, and in most cases a statutory severance payment. Employees dismissed without valid grounds can bring a claim before the Conseil de Prud'hommes (French labour tribunal).
For international employers operating in France, the CDI is the contract form expected by social-security bodies such as URSSAF and by the applicable convention collective (sectoral collective agreement). Misclassifying a recurring fixed-term arrangement as a series of CDDs rather than a CDI can expose the employer to reclassification risk and back-payment of benefits.