Ireland Tax & Filing Deadlines
Every Ireland statutory deadline a founder needs to know. Penalties, checklists and source links to Revenue (Revenue Commissioners) and Companies Registration Office (CRO).
Form CT1 — Corporation Tax Return
Annual Corporation Tax return for Irish companies, filed via ROS within 9 months of accounting period end (specifically the 23rd of the ninth month for ROS filers).
Form B1 — Annual Return (CRO)
Annual return filed with the Companies Registration Office confirming company details and accompanied by financial statements. Mandatory for every Irish company regardless of trading activity.
VAT Bi-Monthly Return
Standard VAT return covering 2-month periods (Jan-Feb, Mar-Apr, May-Jun, etc.), filed via ROS by the 19th (or 23rd ROS) of the month following the period end.
Preliminary Tax (Companies)
Advance Corporation Tax payment due one month before company year-end (specifically the 23rd of that month for ROS users). 90% of current year liability or 100% of prior year for small companies.
Form 11 — Self Assessment
Annual income tax return for Irish self-employed people, company directors, and individuals with non-PAYE income. Filed via ROS by 31 October each year (extended to mid-November for ROS pay-and-file).
Monthly PAYE Liability (Form P30 successor)
Monthly PAYE/PRSI/USC remittance under PAYE Modernisation. Revenue calculates the liability from your real-time payroll submissions; you confirm and pay by the 14th (paper) or 23rd (ROS) of the following month.
Annual Return of Trading Details (RTD)
Annual VAT summary listing total supplies and acquisitions by VAT rate. Due 23 days after the end of the company's accounting period (linked to the company year-end, not the calendar year).
RCT Monthly Return (Construction)
Relevant Contracts Tax monthly return for principal contractors in construction, forestry and meat processing. Filed and paid by the 23rd of the month following the period.