How is a Enterprise Architect contractor taxed in the Netherlands?
Your tax treatment depends on your operating structure. Payrolling (agency): a payroll company runs your pay exactly like a permanent employee, applying Box 1 income tax after its fee comes off the top. ZZP'er (freelance): a genuinely different mechanic, ZZP'ers don't pay into the employee social-insurance schemes (WW/WIA/ZW) at all, but do pay a 4.85% Zvw health-insurance contribution on profit, and get the zelfstandigenaftrek and MKB-winstvrijstelling deductions before tax applies. The calculator above shows both side by side.