Preliminary Tax in Ireland: How to Calculate It for Your Company and Yourself

If you own a limited company, you deal with preliminary tax twice: once for the company's corporation tax and once for your own income tax. Most guides cover only sole traders.

This guide covers both: small and large company rules, first-year relief, the director's own figure, and paying on ROS without interest.

What preliminary tax is (and is not)

Preliminary tax is not a separate tax. It is an advance payment of the tax you expect to owe for the current period, paid before the period ends. When you file the final return, you pay any balance or claim back an overpayment.

For a company owner, there are two separate payments:

• The company's preliminary corporation tax, paid during its accounting period.
• Your own preliminary income tax, paid by 31 October with your Form 11.

Preliminary corporation tax for small companies

For preliminary corporation tax, a small company is one whose corporation tax liability for the previous accounting period was not more than €200,000. If that previous period was shorter than 12 months, the liability is annualised to check whether you are under the line.

A small company can base its payment on either:

• 100% of the previous period's liability, or
• 90% of the current period's liability.

The 100% option is the safe choice for most, because the figure is already known. The payment is due 31 days before the end of the accounting period, and by the 23rd of that month. For a company with a 31 December year end, that means 23 November.

Budget 2027 announced an increase in the small company threshold from €200,000 to €350,000, along with a wider top-up option. The start date had not been confirmed when this guide was written, so continue to use €200,000 until Revenue updates its guidance.

Large companies: two instalments

If the previous period's liability was above €200,000, the company is large and normally pays in two instalments when the accounting period is longer than seven months:

• Month 6: by the 23rd of the sixth month, pay either 50% of the previous period's liability or 45% of the current period's liability.
• Month 11: by the 23rd of the eleventh month, pay enough to bring the total up to 90% of the current period's liability.

If the accounting period is under seven months, the company pays 90% in a single instalment.

Growing companies get caught out here: one strong year pushes them over the threshold, and the next year's payments depend on profits they can only estimate. Good monthly figures are the best protection.

First-year relief for new companies

A new company does not have to pay preliminary tax for its first accounting period if its corporation tax for that period is less than €200,000. You file and pay the full liability with your first return.

The catch comes in year two. Suppose a company's first-year liability is €10,000:

• Year one: no preliminary tax. The €10,000 is paid in full when the first return is filed, in the company's second year.
• Year two: preliminary tax of €10,000 (100% of year one) is due by month 11.

That is €20,000 leaving the company within a few months. Our first-year compliance calendar shows how the dates line up, and new founders should also look at SURE start-up relief.

Preliminary tax for directors and the self-employed

Your own preliminary tax ireland payment is due by 31 October each year, at the same time you file last year's Form 11. To avoid interest, pay at least the lowest of:

• 90% of your tax for the current year,
• 100% of your tax for the previous year, or
• 105% of your tax for the year before last, but only if you pay by direct debit and that year's tax was not nil.

So, how much preliminary tax should i pay? If your income is stable, 100% of last year is the simplest safe harbour. If you file and pay through ROS, you get a later date set by Revenue each year (18 November 2026 for the most recent deadline).

How you split salary and dividends affects this figure. See our guide to paying yourself from your company.

How to calculate and pay preliminary tax on ROS

There is no official preliminary tax calculator, but the working is simple:

1. 1Find last period's final liability from the company's return, or your own Form 11.
2. 2Estimate this period's liability from up-to-date management figures.
3. 3Apply the safe harbours and pay the lower qualifying amount.

For how to pay preliminary tax on ros for a company: log in, go to Payments and Returns, choose Corporation Tax, and select the correct accounting period. If the period is not listed, ask Revenue to open it through MyEnquiries first, or the payment may be applied to the wrong period. For yourself, preliminary tax is paid as part of your Form 11 on ROS.

Underpay and Revenue charges interest at 0.0219% per day on the shortfall. A simple fix is to set aside a fixed amount each month, based on your management figures. Our CT1 and corporation tax deadline calendar lists every date.

Frequently Asked Questions

Accurate books mean an accurate figure

Your preliminary tax is only as good as the numbers behind it. Our bookkeeping packages give you monthly figures you can rely on, which beats any preliminary tax calculator and means your preliminary tax ireland payments are right first time. Starting out? Click here to price your company formation.