What is preliminary tax in Ireland?

## What Is Preliminary Tax in Ireland?

Preliminary tax is an advance payment of your expected tax liability for the current tax year, required before that tax year actually ends. Revenue requires it to ensure tax is collected on a current-year basis rather than entirely in arrears.

For self-employed individuals and company directors, preliminary tax is a cornerstone of the self-assessment system. Getting it wrong is one of the most common and costly mistakes sole traders and directors make.

## Who Must Pay Preliminary Tax?

Preliminary tax applies to:

• **Self-employed sole traders and partnerships** filing under self-assessment
• **Company directors** with non-PAYE income above certain thresholds
• **Individuals with significant rental, investment, or other non-PAYE income**
• **Companies** paying corporation tax (separate rules apply)

If all your income is taxed under PAYE and you have no other income sources, preliminary tax generally does not apply to you.

## Individual Preliminary Tax: The Rules

For individuals (sole traders, directors, landlords), preliminary tax for a given tax year is due by 31 October of that same year via Revenue Online Service (ROS).

You must pay at least the lower of:

• **90% of your final liability** for the current tax year, or
• **100% of your prior year liability**, or
• **105% of your pre-preceding year liability** (only available for direct debit payments)

Most people use the 100% prior-year safe harbour because it is predictable and eliminates the risk of underpayment surcharges.

## The Year-Two Cash Flow Trap

• The balance of your year-one liability (the shortfall from year one's preliminary payment)
• The preliminary tax for year two, based on 100% of your year-one liability

This creates a situation where you owe two years of tax in a single October payment. A sole trader who earned €60,000 in year one might face a combined bill of €15,000 to €25,000 or more in year two, depending on tax bands, USC, and PRSI.

Planning for this is essential. Set aside at least 30-40% of net income from your first day of trading.

## Corporation Tax Preliminary Tax Rules

Companies face different rules depending on their size:

Small companies (corporation tax liability of €200,000 or less in the prior year): - First preliminary tax instalment: 90% of the prior year's liability or 50% of the current year's estimated liability, due on the 23rd of the month 31 days before year-end for online filers - Balance of tax: due within nine months and 23 days after year-end

Large companies (corporation tax liability exceeding €200,000 in the prior year): - First instalment: 45% of the estimated current year liability, or 50% of prior year liability, due in month six of the accounting period - Second instalment: bringing total payments to 90% of current year liability, due in month 11 - Balance of tax: due nine months and 23 days after year-end

## Surcharges and Interest for Underpayment

If your preliminary tax payment falls below the required minimums, Revenue charges interest at 0.0219% per day on the shortfall. This compounds quickly on large underpayments.

For individuals, an additional surcharge of 5% (up to €12,695) applies if your preliminary tax falls below the minimum and your final return is filed late.

## How to Pay Preliminary Tax

All preliminary tax payments must be made through Revenue Online Service (ROS). You cannot pay by cheque for amounts due online.

For self-employed individuals, preliminary tax is declared and paid via the Form 11 online return, due by 31 October. If you use ROS to file and pay, you benefit from an extended deadline of approximately mid-November (the exact date is announced by Revenue each year, typically two to three weeks after 31 October).

## Practical Tips for Managing Preliminary Tax

• **Set up a separate tax savings account** from day one and transfer 30-40% of every payment you receive
• **Use 100% of the prior year as your default** safe harbour to avoid surprises
• **Review your year-two position** in Q2 of your second year of trading so you can build reserves
• **Use accounting software like AccountsOS** to monitor your estimated tax position throughout the year, not just in October
• **Consider a direct debit arrangement** with Revenue if you want to use the 105% pre-preceding year option and smooth payments over the year