Trade posts in coastal or important Silk Road counties can generate a large trade income at a very low construction price. Taxes paid by vassals can be seen in the liege's 'Vassals' tab, and totals for each vassal government type are shown in the liege's demesne screen. Also, a vassal pope or antipope will only pay you taxes if he has a positive opinion of you.

Theocracies are relatively rich and decently powerful, but if Catholic, they will only pay you taxes if they prefer you to the Pope, which is rarely the case.Merchant republics also only pay half the republic tax rate, generating little more tax income than a rich city even when large. Republican vassals, to the contrary, are militarily weak and excellent for making money, but feudal rulers are limited to Feudal vassals usually generate little income regardless of tax rate, and are better at providing you with large levies.

(Special rules apply to Catholic theocracies, see below.) Tax rates are part of your demesne laws and set separately for each government type with Conclave enabled, high tax rates reduce the maximum liege levy, otherwise there is no downside except reduced opinion of you. Your vassals pay you taxes based on your tax rates and their income, combined with their opinion of you - negative opinion means less taxes than usual.

Victoria 2 economic policy