Ireland: Your responsibility

An adviser can prepare the claim, write the technical case and file the return as your agent. None of that moves the claim out of the company's name: the R&D corporation tax credit is claimed by the company in its own return,1Source 1Revenue, Tax and Duty Manual Part 29-02-03, Research and Development (R&D) Corporation Tax Credit (April 2026), section 2.6; the definition of R&D activities is in section 766 of the Taxes Consolidation Act 1997, via Revenue's Notes for Guidance, Part 29. and if Revenue later finds that the credit was overclaimed, your company repays it. The questions on who signs the claim and can we see the full claim before filing? are about making that responsibility real. The people who did the work read the technical descriptions before the return goes in, and the company keeps a copy of what was filed.

• Making the claim. The claim must be made within 12 months from the end of the accounting period in which the expenditure was incurred.1Source 1Revenue, Tax and Duty Manual Part 29-02-03, Research and Development (R&D) Corporation Tax Credit (April 2026), section 2.6; the definition of R&D activities is in section 766 of the Taxes Consolidation Act 1997, via Revenue's Notes for Guidance, Part 29. A claim for an earlier period is usually not open at all, so test any offer to claim for past years against this date (cold calls about unclaimed refunds).
• Amending the return. An amended return must generally be submitted within four years after the end of the chargeable period, unless the provision concerned sets a shorter claim period, as the R&D credit does.2Source 2Revenue, Tax and Duty Manual Part 41A-04-01, Amending returns and self-assessments (November 2025), section 4, Taxes Consolidation Act 1997 section 959V(6).
• Revenue's time limit. A Revenue officer cannot make or amend an assessment more than four years after the end of the chargeable period in which the return was filed, where the return contained a full and true disclosure of all material facts. Where it did not, there is no time limit.3Source 3Revenue, Notes for Guidance, Taxes Consolidation Act 1997, Part 41A (Finance Act 2025 edition), section 959AA. A claim can therefore be looked at well after the credit has been paid, which is why review support in the engagement letter matters (is review support included?).

If the credit, or part of it, was not due, Revenue claws back the additional tax, with interest running from the date Revenue paid the credit until it is repaid, and penalties can apply.4Source 4Revenue, Tax and Duty Manual Part 29-02-06, R&D tax credit: clawback of relief (November 2022), sections 2, 5 and 6: clawback, interest under section 766(7B)(d), penalties under section 1077E. Whether the adviser's fee comes down too depends on the engagement letter, not on Revenue: see what happens to the fee if the claim is reduced?

The law also provides a penalty for any person who deliberately assists in or induces the making of an incorrect return.5Source 5Revenue, Notes for Guidance, Taxes Consolidation Act 1997, Part 47 (Finance Act 2025 edition), section 1055: a penalty of EUR 4,000 on any person who deliberately assists in or induces the making of an incorrect return. That penalty is the other person's; it does not pay the company's tax, interest or penalty, and the engagement letter's liability and indemnity clause is where any contribution from the adviser would be found.

Revenue's Code of Practice for Compliance Interventions sets out how a company can correct its own return. Self-correction without penalty is available for corporation tax within 12 months of the filing due date, with written notification, a computation and payment in full; submitting an amended return on ROS does not of itself count as notifying Revenue. After that, a qualifying disclosure, made in writing and signed with a declaration and payment of the tax and interest, is the route, and it is unprompted if made before notice of a compliance intervention.6Source 6Revenue, Code of Practice for Revenue Compliance Interventions (effective 1 May 2022), sections 2.2, 2.2.1, 2.8 and 2.9. Take advice before you use either route: the correcting a claim page sets out what to settle first, including what the engagement letter says about the fee on the corrected amount.

If Revenue reviews the claim within the time limits above, it can ask for the evidence behind it. Keep the return as filed, the technical case, the cost workings, the project and time records they rest on, and the engagement letter. Ask for anything the adviser holds that you do not (ownership of records and work).

• If your claim is reviewed and complaints about an adviser in Ireland
• Claim reduced on review and if you are charged a penalty
• The true cost of a claim

Sources

1. Revenue, Tax and Duty Manual Part 29-02-03, Research and Development (R&D) Corporation Tax Credit (April 2026), section 2.6; the definition of R&D activities is in section 766 of the Taxes Consolidation Act 1997, via Revenue's Notes for Guidance, Part 29.   Back
2. Revenue, Tax and Duty Manual Part 41A-04-01, Amending returns and self-assessments (November 2025), section 4, Taxes Consolidation Act 1997 section 959V(6).  Back
3. Revenue, Notes for Guidance, Taxes Consolidation Act 1997, Part 41A (Finance Act 2025 edition), section 959AA.  Back
4. Revenue, Tax and Duty Manual Part 29-02-06, R&D tax credit: clawback of relief (November 2022), sections 2, 5 and 6: clawback, interest under section 766(7B)(d), penalties under section 1077E.  Back
5. Revenue, Notes for Guidance, Taxes Consolidation Act 1997, Part 47 (Finance Act 2025 edition), section 1055: a penalty of EUR 4,000 on any person who deliberately assists in or induces the making of an incorrect return.  Back
6. Revenue, Code of Practice for Revenue Compliance Interventions (effective 1 May 2022), sections 2.2, 2.2.1, 2.8 and 2.9.  Back