Persons who have a domicile abroad and are delegated by for-eign subjects as experts with specific knowledge to provide professional assistance to persons resident or based in this country, and who stay in the territory of the Czech Republic for the sole purpose of professional assistance are regarded as taxpayers liable only to taxation of incomes from sources in the territory of the Czech Republic. The law extensively stipulates which incomes are not taxed, and which are exempt from taxation, and as well the circumstances under which exemption can be applied. When a taxpayer has incomes from two or more sources, the tax base is derived from their total. The tax base does not include incomes exempt from income tax or incomes taxed by special rates. At the end of a taxation period, every taxpayer is duty-bound to calculate their income tax in tax returns, and pay it to the financial authority.
Advance payments depend on the amount of the last known tax.
Advance income tax payments of employees are deducted by the domestic employer, who in defined cases also makes their annual clearance of the advance paments. Parallel incomes from two or more employers, or parallel wages and other incomes require the employee to hand in tax returns. Under the law, income tax is levied on bodies corporate which are not natural persons. The Czech National Bank is exempt from income tax. Public commercial companies do not pay tax on their income as bodies corporate, instead the gross profit is divided among the partners, who include their shares in their tax returns as natural persons or bodies corporate.