Preliminary tax for companies: how much, and when
A small company, one whose corporation tax for the previous period was €200,000 or less, pays preliminary tax in one instalment by the 23rd of the month before its year end. It pays the lower of 100% of last year's tax or 90% of this year's.
What preliminary tax is
Companies pay corporation tax on account, before the year ends, rather than all at once when the CT1 is filed. The balance is then paid with the CT1, 9 months after the year end.
Small companies
A small company is one whose corporation tax liability for the previous accounting period was €200,000 or less. It pays preliminary tax in one instalment, 31 days before the end of its accounting period and no later than the 23rd of that month. For a 31 December year end, that's 23 November.
The amount is the lower of:
- 100% of the corporation tax for the previous accounting period, or
- 90% of the corporation tax for the current period.
Large companies
A company whose previous-period liability was over €200,000 pays in two instalments: the first by the 23rd of the sixth month of the period, and the second by the 23rd of the eleventh month, bringing the total to 90% of the final liability.
New companies
A new company doesn't pay preliminary tax for its first accounting period if its corporation tax for that period is under €200,000. It pays the full amount when it files its first CT1.
Getting it right
Paying too little preliminary tax means interest on the shortfall. On our Medium and Large plans, a pre-year-end tax planning review is included, so the amount is worked out before it's due.
Last checked 13 November 2026. This guide is general information, not advice for your company. Tax rules change, so check with us or Revenue before acting.