Accounting Deadlines for Companies and Sole Traders in Ireland: Key Dates You Can’t Afford to Miss

Miss an accounting deadline in Ireland and you’re not just paying late fees. You could lose your audit exemption, face surcharges on your tax bill, or trigger a Revenue compliance intervention. The costs compound quickly, and they’re entirely avoidable.

Whether you run a limited company or operate as a sole trader, the Irish tax and accounting calendar is packed with filing dates that demand attention. This guide sets out every key deadline, explains what happens if you miss them, and gives you a practical system for staying compliant year-round.

Key accounting deadlines table for Ireland

Here’s an at-a-glance summary of the most important accounting deadlines for companies and sole traders in Ireland. Bookmark this, print it, or hand it to your accounting team.

Always verify current-year dates on the Revenue calendar and CRO website, as exact payment dates can shift when they fall on weekends or bank holidays.

CRO Annual Return deadline for limited companies

Every Irish limited company must file an annual return with the Companies Registration Office (CRO). Your filing deadline is within 56 days of your ARD (Annual Return Date), which is the date assigned to your company when it was incorporated.

The annual return includes:

• Form B1 with up-to-date company details (directors, secretary, registered office, shares)
• Financial statements for the relevant accounting period, signed by a director

Getting this right requires planning. Your year-end accounts need to be finalised, reviewed, and approved by directors before the filing deadline arrives. If your bookkeeping is months behind, you’re already in trouble.

What happens if you miss the CRO deadline?

Late filing carries immediate financial consequences. The CRO charges a €100 penalty the moment your 56-day window closes, followed by €3 per day for every day thereafter, up to a maximum of €1,200.

But the bigger cost is losing your audit exemption for the following two financial years. An audit typically costs €2,000 or more per year, so a single late filing can easily cost a small company €5,000+ in avoidable fees. Beyond that, persistent late filing can affect your ability to secure bank lending, win public tenders, or maintain tax clearance.

Corporation tax (CT1) deadline and preliminary tax for companies

Limited companies must file a Corporation Tax Return (CT1) for each accounting period. The filing deadline is the 23rd of the 9th month after your accounting period ends when you file and pay online through ROS (21st for paper filers). The balance of corporation tax due is payable on the same date.

Preliminary corporation tax works differently depending on company size:

• Small companies (prior year CT liability ≤ €200,000): One instalment due by the 23rd of the month before your year-end. Pay either 100% of prior year liability or 90% of current year liability.
• Large companies (prior year CT liability > €200,000): Two instalments. First due in the 6th month of the accounting period (50% of prior year or 45% of current year). Second due in the 11th month, bringing the total to 90%.

Don’t wait for final accounts to estimate your preliminary tax. Use management accounts or your accountant’s projections to avoid underpayment and the interest charges that follow. A start-up in its first accounting period with corporation tax under €200,000 is exempt from preliminary tax, which helps with early-stage cashflow.

What happens if you file or pay corporation tax late?

Late payment triggers interest on the tax owed from the due date. Late filing can result in penalties and interest charges, and significantly increases your chances of a Revenue compliance intervention. If multiple periods are outstanding, the situation escalates quickly.

Income tax return deadline for sole traders (Form 11)

If you’re a sole trader in Ireland or have any self-employed income, you must file an annual tax return using Form 11. The self-assessment system means you calculate your own tax liability, file your return, and pay what’s due.

For the 2025 tax year:

• Paper deadline: 31 October 2026
• ROS deadline (file and pay online): 18 November 2026

You must both file and pay through Revenue Online Service to qualify for the ROS extended deadline. Filing your tax return online but paying by cheque does not get you the extension.

The Form 11 covers trading income, other taxable income, allowable business expenses, capital allowances, and any tax credits or reliefs. You also pay preliminary tax for the current year at the same time, covering your estimated income tax, USC, and PRSI for 2026.

What records do you need?

Good record-keeping makes filing straightforward. At a minimum, you should maintain:

• Sales and income records with supporting invoices and receipts
• Business expense records, categorised and with proof of payment
• Bank statements reconciled to your books and records
• Mileage logs if you claim vehicle expenses
• Home office calculations if you work from home

What happens if you file Form 11 late?

Revenue applies surcharges for late filing. If your income tax return is less than two months late, the surcharge is 5% of your tax bill, capped at €12,695. More than two months late, and it doubles to 10%, capped at €63,485. Interest also accrues on any unpaid balance from the original due date.

VAT return deadlines: when to file VAT3 in Ireland

If you’re registered for VAT, you must file VAT returns and make payments on time. The default frequency is bi-monthly, covering six taxable periods per year: January/February, March/April, May/June, July/August, September/October, and November/December.

For ROS filers, each VAT3 return and payment is due by the 23rd of the month after the taxable period ends. So for the January/February period, your return and payment are due by 23 March. Non-ROS filers have an earlier deadline of the 19th.

Revenue may also assign you a different filing frequency (monthly, 4-monthly, 6-monthly, or annual) depending on your turnover and VAT profile. Regardless of frequency, the principle is the same: file on time and pay what’s due.

Common VAT pitfalls that catch business owners include:

• Reclaiming input VAT without valid invoices
• Applying the wrong VAT rate to goods and services
• Missing reverse charge obligations on cross-border services
• Filing on a cash basis when the invoice basis applies (or vice versa)

What happens if you miss VAT deadlines?

Late filing of a VAT return carries a penalty of up to €4,000 per return. Interest applies to any late payment. Revenue may also delay VAT refunds where returns are outstanding, creating further cashflow pressure. If multiple VAT returns go unfiled, expect increased Revenue scrutiny.

Employer PAYE, PRSI, and USC deadlines

If you have employees, including directors on payroll, you have ongoing obligations for PAYE, PRSI, and USC. Ireland operates a real-time payroll reporting system, which means you must submit payroll information to Revenue on or before each pay date.

Employer tax payments are due by the 14th of the month following the pay period (or the 23rd if you file and pay online through ROS). Quarterly remitters follow the same pattern at quarter-end.

Missing payroll submissions creates problems for your employees’ tax records and can lead to incorrect tax credits being applied. Late payments attract interest and may trigger enforcement activity from Revenue.

What if you can’t pay your tax liability on time?

Cashflow pressure is real, especially for growing businesses. If you can’t meet a tax due date, the worst thing you can do is ignore it.

• File on time even if you can’t pay. Late filing surcharges are separate from late payment interest. Filing on time avoids the surcharge.
• Separate trust taxes from trading taxes. VAT and PAYE/PRSI are collected on behalf of Revenue. Falling behind on these is treated more seriously than being late with your own income tax or corporation tax.
• Contact Revenue early. Revenue offers phased payment arrangements for businesses that engage proactively. Waiting until enforcement begins limits your options.
• Get professional advice. If multiple periods are building up with penalties and interest, an accountant can help you manage your tax obligations, negotiate with Revenue, and get a realistic payment plan in place.

Frequently asked questions

What deadlines apply if I’m both a sole trader and VAT-registered?

You’ll have multiple return deadlines running in parallel. Your Form 11 income tax return is due annually (31 October or 18 November via ROS), while your VAT returns are typically due bi-monthly by the 23rd of that month after each period. Preliminary tax for the current year is also due at the pay and file deadline. A compliance calendar is essential to avoid penalties and interest charges.

Do I still need to file returns if I made a loss or had no activity?

In most cases, yes. Limited companies must still file a CRO annual return and CT1 regardless of trading activity. Sole traders with a tax obligation from previous years or other income sources must still file a return. Filing a nil return is far better than not filing at all.

Is the deadline different if I file through an accountant?

No. The filing dates are the same whether you prepare the return yourself or your accountant does it. ROS is the platform; the legal responsibility remains with the taxpayer or company. However, a good accountant will manage your deadlines in Ireland proactively, ensuring everything is prepared well in advance of the due date.

What’s the difference between CRO annual returns and Revenue tax returns?

The CRO annual return (Form B1) is a company compliance filing with financial statements, submitted to the Companies Registration Office. Revenue tax returns (CT1, Form 11, VAT3) are separate filings for tax reporting and payment, submitted through Revenue Online Service. Both are mandatory, and both have different filing deadlines and consequences for late filing.

What records should I keep to stay compliant?

At a minimum: sales invoices, purchase receipts, bank statements, payroll records, VAT records, and any contracts or agreements relevant to your business. Revenue requires you to retain records for six years. Using cloud-based accounting software like Xero makes this significantly easier and reduces the year-end scramble.

How an accountant helps you stay on top of deadlines

The real value of working with an accountant isn’t just filing returns. It’s never having to worry about what’s due and when. A proactive accounting team will:

• Set up a compliance calendar covering every CRO, Revenue, and payroll deadline for your business
• Prepare year-end accounts and file annual returns well before the ARD
• Handle CT1, Form 11, and VAT3 preparation with built-in review time
• Estimate preliminary tax accurately so you’re not overpaying or underpaying
• Run monthly or quarterly bookkeeping so nothing piles up at year-end
• Send reminders before key dates, not after

If your current accountant only contacts you at year-end, you’re exposed to exactly the kind of deadline pressure that causes expensive mistakes. A business owner shouldn’t have to track return filing dates manually when there’s a better way.

Need help managing your accounting deadlines?

At Kinore, we build deadline management into every client relationship. Whether you’re a sole trader filing your first annual tax return or a growing company juggling CRO, corporation tax, VAT, and payroll, we make sure nothing slips through the cracks.

Book a consultation and let’s set up a system that keeps you compliant, avoids penalties, and frees you to focus on running your business.

The information provided in this article is for general guidance and informational purposes only. It does not constitute professional accounting, tax, or financial advice, and should not be relied upon as a substitute for advice tailored to your specific circumstances. While we take care to ensure the content is accurate and up to date at the time of publication, legislation, tax rates, thresholds, and compliance requirements in Ireland can change.