What are some limitations that could occur during onboarding in France?

When onboarding an employee in France: 

• We cannot backdate employment agreements.
• We're unable to add Allianz as a benefit. The employee cannot choose their mutuelle unless they fall into an exemption category (pending due to migration).
• We're unable to include a percentage amount for bonuses as this needs to be a specific amount. Alternatively, this can be documented between the employee and the Customer. 
• Prior work done before the start date cannot be paid as a “sign-on bonus”.
• A health check is required within three months of their start date. 
• The employee needs to be registered in payroll at least 5-8 business days before their start date.