Short answers to the questions the academy is asked most about Ireland's R&D corporation tax credit, grouped the way the country guide is organised: eligibility, costs and calculation, claiming and deadlines, and reviews. Each answer gives the rule in a sentence or two and links to the page that covers the subject in full, with the official sources. The answers describe the rules for accounting periods beginning on or after 1 January 2024 unless they say otherwise. This page carries FAQPage structured data.
Eligibility
Who can claim the R&D corporation tax credit?
Companies within the charge to Irish corporation tax that carry on qualifying R&D activities. There is no size test and no minimum spend. Individuals and partnerships cannot claim. See eligibility.
What counts as qualifying R&D?
Systematic, investigative or experimental activities in a field of science or technology that are basic research, applied research or experimental development, seek to achieve scientific or technological advancement and involve the resolution of scientific or technological uncertainty. Revenue calls this the science test. See the science test.
Does the project have to succeed?
No. An attempt to resolve a genuine uncertainty qualifies whether or not it succeeds. The R&D ends when the uncertainty is resolved or the work is abandoned, and expenditure after that point is ordinary development with no credit.
Is software development eligible?
Only where it resolves a scientific or technological uncertainty in computer science or software engineering. Revenue's guidance states that business application software, routine maintenance and development using known methods and tools do not qualify. See industries.
Can work done abroad be included?
Only work carried on in Ireland or another EEA state, and only where the expenditure is not relieved against tax elsewhere. See eligibility.
Costs and calculation
Which costs qualify?
Revenue expenditure incurred wholly and exclusively in carrying on the R&D, including staff emoluments apportioned to the activities, materials, directly consumed costs and plant and machinery used in the R&D. Subcontracted work is capped at the greater of 15% of the company's own spend or €100,000, and third level work at the greater of 5% or €100,000. Grant-funded expenditure and general overheads are excluded. See eligible expenditure.
How much is the credit?
30% of qualifying expenditure for accounting periods beginning on or after 1 January 2024, and 35% where the corporation tax return filing date is on or after 23 September 2027, which typically means accounting periods ending on or after 31 December 2026. See payable credit instalments.
Is the credit paid in cash?
Yes. The credit is paid in three instalments, each either offset against corporation tax or repaid as the company elects. The first is the greater of 50% of the claim or a fixed threshold: €75,000 for periods commencing on or after 1 January 2025 that end before 31 December 2026, and €87,500 where the 35% rate applies. See payable credit instalments.
Do buildings qualify?
Not under the main credit. A separate credit applies to expenditure on the construction or refurbishment of buildings used for R&D, with a minimum R&D use condition over a set period and a clawback if the use stops or the building is sold within 10 years. Plant and machinery used in the R&D sits inside the main credit, apportioned to R&D use. See buildings and plant.
What is the Knowledge Development Box?
A separate relief that taxes profits from qualifying intellectual property developed through R&D at a reduced effective rate. It sits alongside the credit, not inside it. See Knowledge Development Box.
Claiming and deadlines
Do we have to tell Revenue before we claim?
If you are claiming for the first time or have not claimed in the previous 3 years, yes: notify Revenue at least 90 days before the claim, using the prescribed form. See how to claim.
What is the deadline?
Within 12 months of the end of the accounting period in which the expenditure was incurred. The claim is made on the corporation tax return and cannot be made or increased after the 12 months. See deadlines.
Where is the claim made?
In the research and development panel of the Form CT1, with the instalment elections and any surrender to key employees. No technical report is filed with the return, but Revenue expects one to exist and may ask for it. See how to claim.
Can we surrender the credit to employees?
Yes, within limits. A company can surrender part of its credit to key employees who spend most of their time on R&D, subject to conditions including a floor on the employee's effective tax rate. See eligible expenditure.
Reviews
What happens if Revenue reviews the claim?
Revenue opens a compliance intervention at one of three levels, may appoint an independent expert to assess the science test, and reconciles the expenditure to the accounts. Records made at the time answer most of it. Disputes go to the Tax Appeals Commission. See Revenue audits and documentation.
Related pages
Official sources
Educational content only, not tax advice. See the disclaimer.