A guide to self-assessment


This section explains the basic principles of the self-assessment system as it applies to Income Tax.

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Under self-assessment, there is a common date for the payment of tax and filing of tax returns. You must file your tax return on, or before, 31 October in the year after the year to which the return relates.

This system, which is known as Pay and File, requires you to:

  • file your return for the previous year
  • make a self-assessment for that year
  • pay the balance of tax for that year
  • and
  • pay preliminary tax for the current 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 further information on filling out the Income Tax Return (Form 11), please see Filing your tax return.

Most individuals must file their Income Tax Return (Form 11) online, through the Revenue Online Service (ROS). There is additional information on Mandatory electronic payment of taxes and filing of tax returns in the Starting a Business section.

Next: Who should register for Income Tax self-assessment?