Ireland's payable instalments and fee timing (brief) | Research Credit Integrity Alliance

Key points

A claim for Ireland's R&D corporation tax credit under section 766C is payable in three annual instalments, and must be made within 12 months of the end of the accounting period in which the expenditure was incurred.12
For accounting periods with a specified return date on or after 23 September 2027, the first instalment is the greater of €87,500 (or the credit, if lower) and 50 percent of the credit; the second is three fifths of the balance; the third is the rest.13
Revenue may examine a claim and make or amend an assessment after the credit has been paid or offset, generally within four years of the end of the period in which the return was filed, and at any time in the cases the legislation sets out.245
Revenue does not approve tax agents, and the professional codes reviewed do not prohibit contingent fees for this work; one identifies a self-interest threat and suggests safeguards.678

How the credit is paid

Claims for accounting periods beginning on or after 1 January 2023 are made under section 766C of the Taxes Consolidation Act 1997. The credit is 30 percent of qualifying expenditure for periods beginning on or after 1 January 2024, and 35 percent for periods with a specified return date on or after 23 September 2027, in general periods ending 31 December 2026 or later.9

The credit is payable in three annual instalments. For each one, the company specifies on its corporation tax return whether it is to be offset against its tax liabilities or paid to it.1 The first instalment becomes available when the return making the claim is filed. Where the following accounting periods are 12 months long, the second and third instalments become payable on filing the returns for those periods; otherwise, 12 and 24 months after the original specified return date.2

Under the formula, a credit of €87,500 or less is available in full in the first year. For a credit of €175,000 or more, half is available in the first year, 30 percent in the second and 20 percent in the third.3

Review after payment

Revenue may examine a claim and make or amend an assessment after the credit has been paid or offset.2 The general time limit is four years after the end of the chargeable period in which the return was filed, where the return contained a full and true disclosure; an assessment can be amended at any time where it did not, and made at any time where there are reasonable grounds to believe there is fraud or neglect.45

If a claim is found not to be authorised, the company may be charged to tax under Case IV of Schedule D on four times the unauthorised amount, with interest from the date the credit was paid or offset.2 Penalties under section 1077F may be charged on amounts offset, amounts paid and amounts claimed but not yet paid.10

How fee timing can interact with the instalments

We did not find any Irish statutory or Revenue rule on how an adviser who prepares an R&D claim is paid. Revenue's guidance states that agents and advisers may not directly receive refunds of their clients' business taxes.6 We also did not find published data on the fee terms used for Irish R&D claims.

The following arithmetic is illustrative, with round numbers. On a credit of €500,000, the instalments are €250,000, €150,000 and €100,000.3 A fee of 20 percent of the total credit is €100,000. If it is invoiced at filing, it equals 40 percent of the first instalment, and it falls due about two years before the last instalment arrives. For a calendar year company claiming for 2026 and filing in 2027, the general four year period for Revenue to make or amend an assessment would, on the rules above, run to the end of 2031.4

If Revenue later reduced that credit to €250,000, a 20 percent fee on the credit allowed would be €50,000; whether the difference is returned depends only on the engagement terms. A fee calculated on each instalment as paid generates no fee on instalments Revenue does not pay, but raises the same question about instalments later recovered.

Fee terms can instead follow the instalments, for example by invoicing a share of each instalment when it is paid or offset. Such terms delay the adviser's payment, expose the adviser if the company stops trading, and add administration.

The case for success fees

Success fees let a company with little cash obtain specialist help and pay only if the claim produces value. They tie the adviser's reward to the result and move the risk of an unsuccessful claim to the adviser. Most of the work precedes filing, so a fee due at filing matches when the adviser bears the cost. These are arguments about incentives and cash flow, not about the conduct of any adviser.

The Chartered Accountants Ireland Code of Ethics states that contingent fees are used for certain non-assurance services but might create a self-interest threat to objectivity in certain circumstances, and lists safeguards such as independent review and advance written agreement on the basis of remuneration.7 The Irish Tax Institute's published Code leaves the method of charging to each member and asks for the fee basis to be set out in the engagement letter.8

What the record shows

The record shows that Ireland pays larger R&D credits over three years, that Revenue can review a claim after payment, and that a company whose credit is reduced faces a tax charge, interest and possible penalties.23410 It shows that the timing of an adviser's fee is left to the engagement terms.68 A fee calculated on the total credit and due at filing can therefore fall due before most of a large credit is received and before Revenue's review period has passed. We found no published data on which fee terms are used.

References

Revenue Commissioners, Tax and Duty Manual Part 29-02-03, Research and Development (R&D) Corporation Tax Credit (last updated April 2026), section 2.3. 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, Notes for Guidance, Taxes Consolidation Act 1997, Finance Act 2025 edition, Part 29 (December 2025), section 766C, subsections (6), (9) to (11) and (16), pages 32 to 35. 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, Research and Development (R&D) Corporation Tax Credit (last updated April 2026), section 2.3.1, Examples 6 and 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, Notes for Guidance, Taxes Consolidation Act 1997, Finance Act 2025 edition, Part 41A (December 2025), section 959AA, page 17. https://www.revenue.ie/en/tax-professionals/documents/notes-for-guidance/tca/part41a.pdf (accessed 11 October 2026). Back
Revenue Commissioners, Notes for Guidance, Taxes Consolidation Act 1997, Finance Act 2025 edition, Part 41A (December 2025), section 959AD, page 19. https://www.revenue.ie/en/tax-professionals/documents/notes-for-guidance/tca/part41a.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 and 14, pages 3 and 10. 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), paragraphs 330.8 A1 to 330.8 A3, pages 69 to 70. https://www.charteredaccountants.ie/docs/default-source/technical-documents/ethics/code-of-ethics---december-2020.pdf?sfvrsn=e828ae7c_2 (accessed 11 October 2026). Back
Irish Taxation Institute, Code of Professional Conduct and Recommended Best Practice Guidelines (taking effect from 15 September 2015), Article 11, Charging for Services, page 23. https://itiprod2storagegroup.blob.core.windows.net/files/Member%20Resources/ITI-Code-of-Professional-Conduct-effective-201509151.pdf (accessed 11 October 2026). Back
Revenue Commissioners, Tax and Duty Manual Part 29-02-03, Research and Development (R&D) Corporation Tax Credit (last updated April 2026), section 1, Introduction. 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 29-02-03, Research and Development (R&D) Corporation Tax Credit (last updated April 2026), section 8.7, Penalty Application. 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