Japan's social insurance system has two broad categories:
Social insurance (narrow sense)
- **Health insurance**: medical costs. ~5% each (employee/employer) - **Employee pension (厚生年金)**: retirement. ~9.15% each - **Long-term care insurance**: 40+ only. ~0.9%
Labor insurance
- **Employment insurance**: unemployment + parental leave. Employee 0.6% / employer 0.95%+ - **Workers' compensation**: work-related injury. Employer only (0.25–8.8% by industry)
Enrollment requirements
- Corporations: mandatory regardless of headcount - Sole proprietors: mandatory once 5+ employees - Part-timers working 20+ hours/week: partial coverage (condition-based)
Filing timing
- **Hire**: within 5 days (health + pension), within 10 days (employment) - **Termination**: within 5 days of day after end date - **Monthly**: deduct in payroll, remit by end of following month
e-Gov e-filing
- HR SaaS (SmartHR, freee HR, jinjer) connect via e-Gov API - Paper-based filing is painful — e-filing is effectively required
Practical tips
- April and October: 算定基礎届 (standard compensation recalc) - File within 5 days for dependent changes - Global HR cannot handle this — Japanese HR SaaS is required