In Europa Universalis II, the census tax is the yearly tax which adds ducats directly into a country's treasury. The census tax is collected on January 1 from every city which a country owns and controls, and which is currently not looted. The census tax does not appear in the financial sumary screen.
The census tax is computed based on the province tax. Each city's tax is computed according to the province tax, but is possibly reduced by a factor called the "census tax multiplier" (CTM). That is, for each city:
census_tax = CTM * province_tax
The CTM is 0 by default (no tax!), and has a maximum of 1.0. These factors apply:
- City has a tax collector: +0.75
- City is in a core province: +0.25
- Country centralization: +0.025 per level
Thus, the tax collector is the main factor, but all countries can get some census tax from their core provinces, and centralized countries can get some additional census tax from all provinces.