Income from oil concessions is based on royalties, generally at the rate of 50% or higher. Individual or local company incomes are tax exempt. Profits of foreign corporations are taxed at rates ranging from 5–55% of the total Kuwait-source profit. The only other tax is a 5% levy on a shareholding company's profit payable to the Kuwait Foundation for Scientific Research. Kuwaiti citizens are exempt from paying taxes. The government passed a law to introduce limited taxation in 2000, in the form of sales taxes.