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UK vs Ireland

How the United Kingdom and Ireland compare on adviser fees, the people who prepare research and development claims, and the checks on those claims, set out side by side with official sources.

On this page
  1. Where they differ
  2. Where they are similar
  3. Sources

This page sets the research and development (R&D) tax reliefs in the United Kingdom beside the R&D corporation tax credit in Ireland. It compares how advisers may be paid, how preparers are registered and identified, and the checks, penalties and appeal routes that apply to claims. Each country page gives the fuller rules and sources.

This table simplifies each country's rules for comparison. See the country pages for detail and sources. Last reviewed pending.

Topic United Kingdom Ireland
Tax authority HM Revenue and Customs (HMRC)1Source 1National Audit Office, Report by the Comptroller and Auditor General: HM Revenue & Customs 2023-24 Accounts, paragraphs 2.2 and 2.21. https://assets.publishing.service.gov.uk/media/6889f286048fff613a4d5b72/Report_by_the_Comptroller_and_Auditor_General.pdf (accessed 11 October 2026). Revenue (the Revenue Commissioners)2Source 2Revenue 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).
Scheme Merged R&D expenditure credit (20 percent) and enhanced R&D intensive support, for accounting periods beginning on or after 1 April 20243Source 3HM Revenue and Customs, Research and Development (R&D) Tax Relief: the merged scheme and enhanced R&D intensive support (last updated 8 January 2026), sections "The merged R&D expenditure credit scheme and enhanced R&D intensive support scheme", "The merged R&D expenditure credit" and "Enhanced R&D intensive support". https://www.gov.uk/guidance/research-and-development-rd-tax-relief-the-merged-scheme-and-enhanced-rd-intensive-support (accessed 11 October 2026). R&D corporation tax credit under section 766C TCA 1997, 30 percent for accounting periods beginning on or after 1 January 2024, claimed on Form CT12Source 2Revenue 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).4Source 4Revenue 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).
Rules on adviser fees No statutory cap or ban identified; R&D tax credits are generally paid only to the claimant company for claims made on or after 1 April 20245Source 5HM Revenue and Customs, Corporate Intangibles Research and Development Manual, CIRD81805, "R&D tax relief: conditions to be satisfied: restriction of nominations and assignments" (updated 25 August 2026). https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81805 (accessed 11 October 2026). No rule on how preparers are paid in section 766C or Revenue's R&D and agent guidance2Source 2Revenue 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).4Source 4Revenue 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).6Source 6Revenue 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).; agents may not receive clients' business tax refunds directly6Source 6Revenue 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).
Professional body rules CIOT and ATT rules allow contingent fees, with care over integrity and objectivity7Source 7Chartered Institute of Taxation and Association of Taxation Technicians, Professional Rules and Practice Guidelines (effective 9 November 2018, updated 1 January 2021), paragraphs 8.1.2 and 8.2.1 to 8.2.5. https://www.att.org.uk/sites/default/files/PRPG%20%28Update%201.1.2021%29%20-%20Final.pdf (accessed 11 October 2026).; the ICAEW Code prohibits them for audit engagements8Source 8ICAEW, ICAEW Code of Ethics 2026 (applies from 1 July 2026), section 330, "Contingent Fees", and paragraph R410.9. https://www.icaew.com/-/media/corporate/files/technical/ethics/code-of-ethics/icaew-code-of-ethics-2026-revisions-highlighted.ashx (accessed 11 October 2026). Chartered Accountants Ireland treats contingent fees as a possible threat to objectivity and prohibits them for audits9Source 9Chartered 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).; the Irish Tax Institute recommends no method of charging10Source 10Irish 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).
Adviser registration Paid advisers who interact with HMRC for clients must register, in windows phased through 202611Source 11HM Revenue and Customs, Check if and when you need to register as a tax adviser with HMRC (last updated 3 September 2026), sections "Who needs to register" and "When to register". https://www.gov.uk/guidance/check-if-and-when-you-need-to-register-as-a-tax-adviser-with-hmrc (accessed 11 October 2026).; no qualification condition12Source 12HM Revenue and Customs, Check if you meet HMRC's conditions to register as a tax adviser (last updated 2 October 2026), section "The registration conditions". https://www.gov.uk/guidance/check-if-you-meet-hmrcs-conditions-to-register-as-a-tax-adviser (accessed 11 October 2026). No Revenue approval system for agents; an agent needs a Tax Advisor Identification Number (TAIN) and a client link6Source 6Revenue 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).
Preparer identification The claim notification and the additional information form ask for contact details of all agents involved13Source 13HM Revenue and Customs, Tell HMRC you want to claim Research and Development (R&D) tax relief (last updated 31 October 2024), sections "Who needs to submit the form", "When to submit the form" and "What information you'll need". https://www.gov.uk/guidance/tell-hmrc-that-youre-planning-to-claim-research-and-development-rd-tax-relief (accessed 11 October 2026).14Source 14HM Revenue and Customs, Additional information you must submit before you claim Research and Development tax relief (last updated 26 September 2025), sections "When to submit", "Who can submit" and "Contact details". https://www.gov.uk/guidance/submit-detailed-information-before-you-claim-research-and-development-rd-tax-relief (accessed 11 October 2026). The details required with a claim do not include the preparer4Source 4Revenue 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).15Source 15Revenue 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).; whether Form CT1 records one is not stated
Claim integrity measures Advance claim notification for first claims and some others13Source 13HM Revenue and Customs, Tell HMRC you want to claim Research and Development (R&D) tax relief (last updated 31 October 2024), sections "Who needs to submit the form", "When to submit the form" and "What information you'll need". https://www.gov.uk/guidance/tell-hmrc-that-youre-planning-to-claim-research-and-development-rd-tax-relief (accessed 11 October 2026).; additional information form on or before the claim, or the claim is invalid16Source 16HM Revenue and Customs, Corporate Intangibles Research and Development Manual, CIRD182000, "R&D Tax Reliefs: reformed reliefs: claims process: additional information form" (updated 25 August 2026), sections "Statutory framework" and "What information is required". https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird182000 (accessed 11 October 2026). Pre-filing notification at least 90 days before a first claim, or after three periods without one4Source 4Revenue 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).15Source 15Revenue 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).; a claim must include all information Revenue may reasonably require4Source 4Revenue 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).
Penalties Up to 30 percent of potential lost revenue for a careless inaccuracy, up to 100 percent if deliberate and concealed17Source 17HM Revenue and Customs, Penalties for inaccuracies in returns and documents: CC/FS7a (updated 21 July 2026), section "How we work out the amount of a penalty", stage 4. https://www.gov.uk/government/publications/compliance-checks-penalties-for-inaccuracies-in-returns-or-documents-ccfs7a/compliance-checks-for-penalties-of-inaccuracies-in-returns-or-documents-ccfs7a-factsheet (accessed 11 October 2026).; adviser penalty for sanctionable conduct since 1 April 202618Source 18HM Revenue and Customs, Compliance Handbook, CH176100, "Sanctionable conduct by tax advisers: Overview", and CH176140, "Commencement date" (manual updated 7 October 2026). https://www.gov.uk/hmrc-internal-manuals/compliance-handbook/ch176100 (accessed 11 October 2026). Unauthorized amounts charged to tax on four times the amount, with tax-geared penalties under section 1077F4Source 4Revenue 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).19Source 19Revenue 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).; penalty under section 1055 for deliberately assisting an incorrect return20Source 20Revenue 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).
Reviews and disputes Each claim risk assessed; compliance checks opened on 17 percent of claims in 2023 to 202421Source 21HM Revenue and Customs, Approach to Research and Development tax reliefs 2023 to 2024 (published 30 October 2024), sections 2.1, 2.4 and 2.5, and Annex B, Theme 5 and Table B.4. https://www.gov.uk/government/publications/hmrcs-approach-to-research-and-development-tax-reliefs-2023-to-2024/approach-to-research-and-development-tax-reliefs-2023-to-2024 (accessed 11 October 2026).; appeal, statutory review, then the First-tier Tribunal (Tax)22Source 22GOV.UK, Disagree with a tax decision or penalty, sections "Disagree with a tax decision" and "Get a review". https://www.gov.uk/tax-appeals/print (accessed 11 October 2026). Science and accounting tests19Source 19Revenue 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).; Revenue may consult independent experts23Source 23Revenue 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).; interventions under Revenue's Code of Practice; appeals to the Tax Appeals Commission24Source 24Revenue 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).

Where they differ

Registration. Paid advisers who interact with HMRC about a client's tax affairs must now register, with registration windows phased through 2026.11Source 11HM Revenue and Customs, Check if and when you need to register as a tax adviser with HMRC (last updated 3 September 2026), sections "Who needs to register" and "When to register". https://www.gov.uk/guidance/check-if-and-when-you-need-to-register-as-a-tax-adviser-with-hmrc (accessed 11 October 2026). Revenue states that it does not operate any system for approving tax agents or advisers; an agent acts through a TAIN and a client link.6Source 6Revenue 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). See Adviser registration by country.

Preparer identification. HMRC's claim notification and additional information form both ask for the contact details of all agents involved in the claim.13Source 13HM Revenue and Customs, Tell HMRC you want to claim Research and Development (R&D) tax relief (last updated 31 October 2024), sections "Who needs to submit the form", "When to submit the form" and "What information you'll need". https://www.gov.uk/guidance/tell-hmrc-that-youre-planning-to-claim-research-and-development-rd-tax-relief (accessed 11 October 2026).14Source 14HM Revenue and Customs, Additional information you must submit before you claim Research and Development tax relief (last updated 26 September 2025), sections "When to submit", "Who can submit" and "Contact details". https://www.gov.uk/guidance/submit-detailed-information-before-you-claim-research-and-development-rd-tax-relief (accessed 11 October 2026). The details Irish law requires with a claim and with the pre-filing notification do not include the identity of anyone who helped prepare it.4Source 4Revenue 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).15Source 15Revenue 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). See Preparer identification by country.

Notification timing. In the United Kingdom a notification, where required, must be made within a period ending six months after the end of the period of account.13Source 13HM Revenue and Customs, Tell HMRC you want to claim Research and Development (R&D) tax relief (last updated 31 October 2024), sections "Who needs to submit the form", "When to submit the form" and "What information you'll need". https://www.gov.uk/guidance/tell-hmrc-that-youre-planning-to-claim-research-and-development-rd-tax-relief (accessed 11 October 2026). In Ireland it must be made at least 90 days before the claim.4Source 4Revenue 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).15Source 15Revenue 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).

Adviser penalties. Since 1 April 2026 HMRC may charge a tax adviser a penalty for sanctionable conduct, meaning conduct intended to bring about a loss of tax revenue.18Source 18HM Revenue and Customs, Compliance Handbook, CH176100, "Sanctionable conduct by tax advisers: Overview", and CH176140, "Commencement date" (manual updated 7 October 2026). https://www.gov.uk/hmrc-internal-manuals/compliance-handbook/ch176100 (accessed 11 October 2026). In Ireland a person who deliberately assists in or induces the making of an incorrect return is liable to a penalty under section 1055.20Source 20Revenue 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). See Penalties by country.

Appeals. A UK company can appeal, ask for a statutory review and then go to the First-tier Tribunal (Tax).22Source 22GOV.UK, Disagree with a tax decision or penalty, sections "Disagree with a tax decision" and "Get a review". https://www.gov.uk/tax-appeals/print (accessed 11 October 2026). Irish tax disputes go to the Tax Appeals Commission.24Source 24Revenue 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).

Where they are similar

No statutory cap or ban on contingent fees for preparing R&D claims was identified for either country. Both limit agents' access to the money: HMRC generally pays R&D tax credits only to the claimant company for claims made on or after 1 April 2024, and Revenue's guidelines state that agents may not receive their clients' business tax refunds directly.5Source 5HM Revenue and Customs, Corporate Intangibles Research and Development Manual, CIRD81805, "R&D tax relief: conditions to be satisfied: restriction of nominations and assignments" (updated 25 August 2026). https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81805 (accessed 11 October 2026).6Source 6Revenue 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). See Contingent fee rules by country.

Both have professional bodies whose codes treat contingent fees as a possible self-interest threat to objectivity and prohibit them for audit engagements: the ICAEW Code in the United Kingdom and the Chartered Accountants Ireland Code of Ethics.8Source 8ICAEW, ICAEW Code of Ethics 2026 (applies from 1 July 2026), section 330, "Contingent Fees", and paragraph R410.9. https://www.icaew.com/-/media/corporate/files/technical/ethics/code-of-ethics/icaew-code-of-ethics-2026-revisions-highlighted.ashx (accessed 11 October 2026).9Source 9Chartered 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).

Both require advance notice from first-time claimants and from some companies that have not claimed for a period, and both require supporting information with the claim, or the claim is not valid.13Source 13HM Revenue and Customs, Tell HMRC you want to claim Research and Development (R&D) tax relief (last updated 31 October 2024), sections "Who needs to submit the form", "When to submit the form" and "What information you'll need". https://www.gov.uk/guidance/tell-hmrc-that-youre-planning-to-claim-research-and-development-rd-tax-relief (accessed 11 October 2026).16Source 16HM Revenue and Customs, Corporate Intangibles Research and Development Manual, CIRD182000, "R&D Tax Reliefs: reformed reliefs: claims process: additional information form" (updated 25 August 2026), sections "Statutory framework" and "What information is required". https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird182000 (accessed 11 October 2026).4Source 4Revenue 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).15Source 15Revenue 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). See Claim integrity measures by country.

The fields HMRC lists for the additional information form do not include the basis or amount of an agent's fee, and no Irish source reviewed requires the claim, the notification or the return to state how the preparer was paid.16Source 16HM Revenue and Customs, Corporate Intangibles Research and Development Manual, CIRD182000, "R&D Tax Reliefs: reformed reliefs: claims process: additional information form" (updated 25 August 2026), sections "Statutory framework" and "What information is required". https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird182000 (accessed 11 October 2026).4Source 4Revenue 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).15Source 15Revenue 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).

Sources

  1. National Audit Office, Report by the Comptroller and Auditor General: HM Revenue & Customs 2023-24 Accounts, paragraphs 2.2 and 2.21. https://assets.publishing.service.gov.uk/media/6889f286048fff613a4d5b72/Report_by_the_Comptroller_and_Auditor_General.pdf (accessed 11 October 2026).  Back
  2. 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
  3. HM Revenue and Customs, Research and Development (R&D) Tax Relief: the merged scheme and enhanced R&D intensive support (last updated 8 January 2026), sections "The merged R&D expenditure credit scheme and enhanced R&D intensive support scheme", "The merged R&D expenditure credit" and "Enhanced R&D intensive support". https://www.gov.uk/guidance/research-and-development-rd-tax-relief-the-merged-scheme-and-enhanced-rd-intensive-support (accessed 11 October 2026).  Back
  4. 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
  5. HM Revenue and Customs, Corporate Intangibles Research and Development Manual, CIRD81805, "R&D tax relief: conditions to be satisfied: restriction of nominations and assignments" (updated 25 August 2026). https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81805 (accessed 11 October 2026).   Back
  6. 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
  7. Chartered Institute of Taxation and Association of Taxation Technicians, Professional Rules and Practice Guidelines (effective 9 November 2018, updated 1 January 2021), paragraphs 8.1.2 and 8.2.1 to 8.2.5. https://www.att.org.uk/sites/default/files/PRPG%20%28Update%201.1.2021%29%20-%20Final.pdf (accessed 11 October 2026).  Back
  8. ICAEW, ICAEW Code of Ethics 2026 (applies from 1 July 2026), section 330, "Contingent Fees", and paragraph R410.9. https://www.icaew.com/-/media/corporate/files/technical/ethics/code-of-ethics/icaew-code-of-ethics-2026-revisions-highlighted.ashx (accessed 11 October 2026).   Back
  9. 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
  10. 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
  11. HM Revenue and Customs, Check if and when you need to register as a tax adviser with HMRC (last updated 3 September 2026), sections "Who needs to register" and "When to register". https://www.gov.uk/guidance/check-if-and-when-you-need-to-register-as-a-tax-adviser-with-hmrc (accessed 11 October 2026).   Back
  12. HM Revenue and Customs, Check if you meet HMRC's conditions to register as a tax adviser (last updated 2 October 2026), section "The registration conditions". https://www.gov.uk/guidance/check-if-you-meet-hmrcs-conditions-to-register-as-a-tax-adviser (accessed 11 October 2026).  Back
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