The standard rate of corporation tax for trading profits is 12.5% for 2003 and thereafter. For certain non-trading profits, as well as profits from mining, certain petroleum activities and dealing in or the development of land, the corporation tax rate is 25%. The Finance Act 2008 introduced a Profits Resource Rent Tax for companies carrying on a petroleum trade. Where applicable, the tax rates range from 5% to 15%, and are in addition to the normal corporation tax rate of 12.5%.

Worldwide capital gains realized by resident companies are subject to corporation tax at the rate of 33% (30% for gains arising before 6 December 2012). An exemption applies where an Irish resident company disposes of a shareholding in a company resident in Ireland, another EU Member State or a country with which Ireland has a tax treaty. To qualify for the exemption, the shareholding must be at least 5% of the share capital of the investee company. The shareholding must not derive its value from Irish real estate and must have been held for a continuous period of 12 months in the 2 years prior to the disposal.