Ireland: Overview

Ireland gives companies a corporation tax credit for qualifying research and development (R&D) expenditure. This page summarizes how a claim is made, what the official sources say about the advisers who prepare claims and how they may be paid, and the questions those sources leave open. Each topic has its own page, listed below, and every source is collected on the Ireland sources page.

The credit and who runs it

The credit is administered by the Revenue Commissioners (Revenue). For accounting periods beginning on or after 1 January 2023, claims must be made under section 766C of the Taxes Consolidation Act 1997 (TCA 1997), or section 766D for buildings and structures.1 Section 766C was inserted by the Finance Act 2022.2 The definitions in section 766, including the meaning of "research and development activities", continue to apply.1

The credit is 30 percent of qualifying expenditure for accounting periods beginning on or after 1 January 2024. Finance Act 2025 raised it to 35 percent for accounting periods whose specified return date is on or after 23 September 2027.3 The credit is paid or offset in three annual instalments, and the company chooses whether each instalment is offset against tax or paid to it.3

A claim is made on the company's corporation tax return, Form CT1, through the Revenue Online Service (ROS), within 12 months of the end of the accounting period in which the expenditure was incurred.14

How advisers are paid

The official sources reviewed for this page do not describe how R&D claim preparers in Ireland charge for their work. They do set some limits on the mechanics of payment:

The credit is claimed by, and paid or offset to, the company. The company specifies in its return whether each instalment is treated as an overpayment of tax or paid to it by Revenue.3
Revenue's guidelines for agents state that agents and advisers are not permitted to receive refunds of their clients' business taxes directly.5

Section 766C, the related Revenue manual and Revenue's guidelines for agents contain no rule on the basis on which a claim preparer may be paid, including any rule on fees calculated as a percentage of the credit.135 The fee rules page sets out what was reviewed.

Professional body rules

Chartered Accountants Ireland applies a Code of Ethics derived from the international code of the International Ethics Standards Board for Accountants (IESBA).6 It states that contingent fees are used for certain types of non-assurance services but might create threats to compliance with the fundamental principles, particularly a self-interest threat to objectivity, and it prohibits contingent fees for audit engagements and for some services to audit clients.6

The Irish Tax Institute's Code of Professional Conduct states that each member is responsible for setting their own fees, that the Institute does not recommend any particular method of charging, and that the engagement letter should set out the proposed fees and how they are calculated.7 See professional body rules.

Who may prepare a claim

Revenue states that it does not operate any system for approving tax agents or advisers. An agent or adviser must have a Tax Advisor Identification Number (TAIN), and a TAIN together with a client link is the process by which a taxpayer authorizes someone to act for it.5 A company does not need an agent.8 See adviser registration and preparer identification.

What a claim must include

The law lists the details a company must give when it claims, including its R&D expenditure on plant or machinery, the emoluments of employees carrying on R&D activities and its remaining R&D expenditure.3 A claim must be a "valid claim", meaning all the information Revenue may reasonably require to decide whether, and to what extent, the credit is due.3

Companies claiming for the first time, and companies that have not claimed in any of the previous three accounting periods, must notify Revenue on a prescribed form at least 90 days before the claim is made.39 See pre-filing notification and claim integrity measures.

Reviews, penalties and appeals

Revenue states that a company must be able to show that its claim meets two tests: the activity is qualifying R&D (the "science test") and the costs have been properly tracked and accounted for (the "accounting test").4 Revenue may consult independent experts on whether expenditure was incurred on R&D activities.10 Compliance interventions follow Revenue's Code of Practice for Revenue Compliance Interventions.411

Where a claim is found not to be authorized, the company may be charged to tax under Case IV of Schedule D on four times the unauthorized amount, and tax-geared penalties under section 1077F can apply.34 A person who deliberately assists in or induces the making of an incorrect return is liable to a penalty under section 1055.12 Disputes about tax go to the Tax Appeals Commission.11 See reviews and audits, expert consultation, Revenue code of practice, penalties and disputes and appeals.

Open questions

The official sources reviewed leave these points unaddressed:

Fee basis. No source reviewed requires a claim, the pre-filing notification or the corporation tax return to state how the preparer was paid.39
Preparer on the claim. The details the law requires with a claim and with the pre-filing notification do not include the identity of anyone who helped prepare it.39 Whether Form CT1 itself records a preparer is not stated in the sources reviewed.
Responsibility. Revenue's Code of Practice states that a taxpayer cannot devolve the responsibility of making a correct return to an agent.11

Sources

Revenue Commissioners, Tax and Duty Manual Part 29-02-03, Research and Development (R&D) Corporation Tax Credit (last updated April 2026), section 1 and section 2.6. https://www.revenue.ie/en/tax-professionals/tdm/income-tax-capital-gains-tax-corporation-tax/part-29/29-02-03.pdf (accessed 11 October 2026). Back
Finance Act 2022 (No. 44 of 2022), section 27(4), inserting sections 766C and 766D into the Taxes Consolidation Act 1997. Irish Statute Book. https://www.irishstatutebook.ie/eli/2022/act/44/section/27/enacted/en/html (accessed 11 October 2026). Back
Revenue Commissioners, Notes for Guidance, Taxes Consolidation Act 1997, Finance Act 2025 edition, Part 29, section 766C, subsections (1), (6), (7), (9), (10), (14) and (17). https://www.revenue.ie/en/tax-professionals/documents/notes-for-guidance/tca/part29.pdf (accessed 11 October 2026). Back
Revenue Commissioners, Tax and Duty Manual Part 29-02-03 (last updated April 2026), sections 8, 8.6.2 and 8.7. https://www.revenue.ie/en/tax-professionals/tdm/income-tax-capital-gains-tax-corporation-tax/part-29/29-02-03.pdf (accessed 11 October 2026). Back
Revenue Commissioners, Tax and Duty Manual Part 37-00-04b, Guidelines for Agents or Advisors acting on behalf of taxpayers (last reviewed September 2026), sections 1, 2 and 14. https://www.revenue.ie/en/tax-professionals/tdm/income-tax-capital-gains-tax-corporation-tax/part-37/37-00-04b.pdf (accessed 11 October 2026). Back
Chartered Accountants Ireland, Code of Ethics, Parts 1 to 4 (applying from 1 March 2020), introductory note and paragraphs 330.8 A1 to A4, R410.10 and R410.11. https://www.charteredaccountants.ie/docs/default-source/technical-documents/ethics/code-of-ethics---december-2020.pdf?sfvrsn=e828ae7c_3 (accessed 11 October 2026). Back
Irish Taxation Institute, Code of Professional Conduct and Recommended Best Practice Guidelines (version taking effect 15 September 2015), Article 11. https://itiprod2storagegroup.blob.core.windows.net/files/Member%20Resources/ITI-Code-of-Professional-Conduct-effective-201509151.pdf (accessed 11 October 2026). Back
Revenue Commissioners, Do you need a tax agent? https://www.revenue.ie/en/starting-a-business/starting-a-business/do-you-need-a-tax-agent.aspx (accessed 11 October 2026). Back
Revenue Commissioners, Research and Development Corporation Tax Credit: Pre-filing Notification Form in respect of a claim to be made under section 766C TCA 1997, form and notes. https://www.revenue.ie/en/companies-and-charities/documents/rd-form-766c.pdf (accessed 11 October 2026). Back
Revenue Commissioners, Notes for Guidance, Taxes Consolidation Act 1997, Finance Act 2025 edition, Part 29, section 766, subsection (7). https://www.revenue.ie/en/tax-professionals/documents/notes-for-guidance/tca/part29.pdf (accessed 11 October 2026). Back
Revenue Commissioners, Code of Practice for Revenue Compliance Interventions (effective 1 May 2022), sections 1, 4.6.2 and 4.11.2. https://www.revenue.ie/en/tax-professionals/documents/code-of-practice-revenue-compliance-interventions.pdf (accessed 11 October 2026). Back
Revenue Commissioners, Notes for Guidance, Taxes Consolidation Act 1997, Finance Act 2025 edition, Part 47, section 1055. https://www.revenue.ie/en/tax-professionals/documents/notes-for-guidance/tca/part47.pdf (accessed 11 October 2026). Back

At a glance

The credit and who runs it

How advisers are paid

Professional body rules

Who may prepare a claim

What a claim must include

Reviews, penalties and appeals

Open questions

Sources

Register your interest

At a glance

The credit and who runs it

How advisers are paid

Professional body rules

Who may prepare a claim

What a claim must include

Reviews, penalties and appeals

Open questions

Sources

More on Ireland

Register your interest