The best known of the personal taxes is Income Tax which operates on the basis of the calendar year as the year of assessment. Individuals must file a Return of Income for each tax year not later than October 31st in the year following the tax year. There are concessions for those who file online.
If a Return for any year of assessment is not submitted or submitted late, the tax liability for that year is subjected to a Surcharge.
A comprehensive summary of Income Tax in the Republic of Ireland would require 200 pages or more.