Each empire that has a capital city maintains a treasury. The treasury grows through taxation. The treasury shrinks by paying out rewards and by conducting research and development. An empire with no capital does not accumulate a treasury.

The treasury is reported as a Government Account balance in the city report of each city that has a bank. Income and expenses of the treasury are shown on the city report.

Taxes are set by the emperor using the Governance (F10) window. An empire with no capital cannot levy taxes. Three kinds of taxes can be set.

	Income tax	Collected on all income earned by citizens employed in empire cities. Each employed citizen earns 25¢ per city report period. Income tax is also collected on rewards paid out to players, at the time the debt is redeemed.
	Sales tax	Collected periodically from every city based on the income spent by its population. Sales tax is also collected on commodity sell transactions, such as when a player sells items at the retail store or when a player sells cargo to cities or other players.
	Subsidy tax	Collected when cargo is sold from a subsidized spacecraft. Subsidized spacecraft are manufactured automatically at spacecraft factories. Privately-owned spacecraft are not subject to subsidy tax. Privately-owned spacecraft are purchased at spacecraft factories using cash.

Taxes accumulate in the city coffers. Once per day, a portion of each city's accumulated taxes are remitted to the empire for deposit into the treasury. When a city is captured, the daily tax revenues that have accumulated and the private funds of the local citizens are split between the conquering players present in the city.

Rewards are established by the emperor. Many different rewards may be posted. These are listed on the Governance (F10) window. As members of an empire earn rewards, a debt is accrued to them by their empire. This debt is collected by visiting a bank that is owned by the empire. There the debt can be redeemed for cronodollars if the bank has the money in its government account. Income tax is collected off government debt when it is redeemed, at the current income tax rate of the empire.