Preliminary Tax Obligations for Income Tax & Corporation Tax

Individuals who file income tax returns and companies who file corporation tax returns have an obligation to pay preliminary tax:

1. Individuals

Preliminary tax is your estimate of the Income Tax, PRSI and USC that you expect to pay for a tax year. You must pay this by 31 October of the tax year in question.

The amount of preliminary tax for a year must be equal to, or more than, the lowest amount of the following:

100% of the tax due for the immediately previous tax year
90% of the tax due for the current tax year

It is necessary that you make a sufficient preliminary tax payment based on the above rules, as we have seen Revenue impose interest on underpayments.

As income tax returns are filed a year in arrears, i.e. your 2023 tax return will be due in October 2024, it is important to note that if you do not make a preliminary tax payment for the year in question, interest at a rate of 0.0219% will be incurred from the date that the payment was due.

For example, your 2023 tax return is due for filing on 31 October 2024. Your preliminary tax payment would have been due for payment on 31 October 2023. If you did not make the payment on 31 October 2023, Revenue may impose interest from 31 October 2023 when you file your return in 2024.

2. Companies

Irish resident companies and non-resident companies must pay Corporation Tax on taxable profits if:

a resident company trades in Ireland
a non-resident company trades in Ireland through a branch or agency
from 1 January 2022, a non-resident company is in receipt of profits or gains in respect of rental property in Ireland.

The rules of when a company should make their preliminary tax payment depends on whether they are classified as a Small Company or Large Company.

Small Companies

A small company is a company whose CT liability is not above €200,000 in the previous accounting period.

Small companies can base their preliminary tax for an accounting period on:

100% of their CT liability for the previous accounting period
90% of their CT liability for the current period (and there is provision for a top up payment to be made).

This must be paid on the 23rd of the eleventh month after the accounting period ended. For example, if the company’s year end is 31 December 2024, preliminary tax is due by 23 November 2024.

Large Companies

Large companies can pay their preliminary CT in two instalments when their accounting period is longer than seven months. The first instalment is due on the 23rd of the sixth month of the accounting period. The amount due is either:

50% of the CT liability for the previous accounting period
45% of the CT liability for the current accounting period.

The second instalment is due on the 23rd of the eleventh month. This will bring the preliminary tax up to 90% of the final tax due for the current accounting period.

For example, if the company’s year end is 31 December 2024, and they are a large company, the first instalment of preliminary tax is due on the 23^rd of June and the 2^nd instalment is due on the 23^rd of November.

If preliminary tax isn’t paid by the above dates, interest is due at a daily rate of 0.0219% on late payments or payments that are not made in full. The interest is calculated by multiplying together the: