They know it. You own property. It's in the data file. Your payroll records go to the government. In the spring, you get a bill.
Taxes are terribly steep.
But why worry, everything is taken care of. All your personal information is in the data bank and accessible by computer. You do not worry about taxes, payments, and medical payments. If you become successful, you pay more. But this is exactly the way it is today, for three million Finnish residents.