Today, 1 September, is a good time to get organised for the month ahead, stay on top of your tax obligations and start preparing for some of the important deadlines coming later in the year.

Starting now gives you more time to review your figures, consider any relevant tax credits and reliefs, and plan for upcoming payments well in advance.

14 September: PAYE, PRSI, USC & LPT

Employers should ensure their monthly return and payment for August 2026 are completed.

For qualifying employers who file and pay online through ROS, the payment deadline is extended to 23 September.

14 September: Dividend Withholding Tax

The Dividend Withholding Tax (DWT) return and payment for relevant distributions made during August are due by 14 September.

If your company pays dividends, this is a good opportunity to make sure distributions are correctly documented and reflected in your tax records.

14 September: Professional Services Withholding Tax

The PSWT F30 monthly return and payment for August 2026 are also due.

PSWT applies to certain professional services where payments are made by accountable persons, including certain public and State bodies.

19 September: VAT

VAT returns and payments may fall due on 19 September, depending on your business’s VAT accounting period. This includes relevant monthly, bi-monthly, four-monthly and annual VAT returns.

For ROS filers, the VAT filing deadline is generally extended to 23 September.

23 September: Relevant Contracts Tax

The RCT monthly return and payment for August 2026, where applicable, are due by 23 September.

RCT is relevant to principal contractors and subcontractors operating in the construction, forestry and meat-processing sectors.

September Corporation Tax Deadlines

Corporation Tax deadlines depend on your company’s accounting period.

During September, Preliminary Corporation Tax is due for accounting periods ending in October 2026. Corporation Tax returns and balancing payments are also due for accounting periods ending in December 2025.

Companies generally file and pay electronically through ROS by the 23rd of the relevant month.

Looking Ahead to the October Income Tax Deadline

September is also a good time for self-employed individuals and other self-assessed taxpayers to start preparing their 2025 Income Tax Return.

The standard Pay & File deadline is 31 October 2026. By this date, taxpayers generally need to:

• File their 2025 Income Tax Return
• Pay any balance of Income Tax due for 2025
• Pay Preliminary Tax for 2026

For taxpayers who file their 2025 Form 11 and make the appropriate payments through ROS, Revenue has extended the deadline to Wednesday, 18 November 2026.

Starting now gives you more time to review your figures, consider relevant tax credits and reliefs and understand your upcoming payments well before the deadline.

Contact Us

Keeping on top of your tax deadlines gives you greater visibility over your finances and more time to plan ahead.

At Gallagher Keane Chartered Accountants, we help businesses and individuals manage their tax obligations and prepare for upcoming deadlines.

Need support with an upcoming tax deadline or your 2025 Income Tax Return? Get in touch with our team.