A guide to self-assessment

Overview

This guide sets out the basic principles of the self-assessment system as it applies to Income Tax (IT) and Capital Gains Tax (CGT). For Corporation Tax (CT), please refer to the Companies and charities section.

Self-assessment is where you make your own assessment of the IT, Universal Social Charge (USC), Pay Related Social Insurance (PRSI) and CGT you should pay for a tax year. You must self-assess when filing your annual tax return. An exception is made where you file a paper return on or before 31 August in the year following the year to which the return relates.

Under self-assessment you must file your tax return on or before 31 October in the year after the year to which the return relates.

You must file Form 11 online through the Revenue Online Service (ROS).

Next: Who should register for self-assessment?