Ireland: Pre-filing notification | Research Credit Integrity Alliance

Some companies must tell Revenue that they intend to claim the research and development (R&D) corporation tax credit before they make the claim. This page sets out the legal basis of the requirement, which companies it applies to, the deadline, what the prescribed form asks for, and how it is filed.

Legal basis and start date

The requirement is in section 766C(17) of the Taxes Consolidation Act 1997 (TCA 1997) for the R&D credit on expenditure, and in section 766D(16) for the credit on buildings and structures.1 Revenue's manual states that it applies for accounting periods beginning on or after 1 January 2024.1 Revenue's guidance page and the prescribed form state the same start date.23

Who must notify

The notification applies to:

companies claiming the credit for the first time; and
companies that have not claimed the R&D credit, under either the earlier section 766 or section 766C, in any of the previous three accounting periods.13

It does not apply where the company has made a claim under section 766 or 766C for any of the three immediately preceding accounting periods.34

Company's position	Notification needed?
Never claimed the R&D credit	Yes1
Claimed in at least one of the previous three accounting periods	No3
Last claimed more than three accounting periods ago	Yes1

The deadline

The notification must be filed at least 90 days before the claim for the credit is made.34 The law defines the "relevant date" as the date 90 days before the claim is made.4

Revenue's manual gives an example. A company that has never claimed intends to make its claim for the accounting period ended 31 December 2026 in its Form CT1 filed on 31 March 2027, so it should file the pre-filing notification on or before 31 December 2026.1

Because the deadline runs from the date the claim is made, and the claim must itself be made within 12 months of the end of the accounting period, the notification also has to be filed early enough to leave 90 days before that 12 month limit.14

What the form asks for

The law requires the particulars specified in the prescribed form, including the company's name, address and corporation tax number, a description of the R&D activities, the number of employees carrying on R&D activities, and details of expenditure met directly or indirectly by grant or other assistance.4

The prescribed form for section 766C claims has these parts:3

Part of the form	Content
Company details	Corporation tax reference number, name and address, and the accounting period concerned
Section 1	Number of employees carrying on R&D activities, number of R&D projects (an estimate if not finalized), and expenditure met by grant or other assistance
Section 2	A description of the qualifying R&D activities: a brief synopsis giving an understanding of the R&D undertaken by the company as a whole, with examples of projects
Section 3	Any other information the company wishes to give
Declaration	Signed on behalf of the company, stating that the form is correct and complete to the best of the signatory's knowledge and belief, with the signatory's status and contact details for queries

The notes to the form repeat the five conditions an activity must meet to be a qualifying R&D activity under section 766(1)(a): systematic, investigative or experimental activities; in a field of science or technology; involving basic research, applied research or experimental development; seeking scientific or technological advancement; and involving the resolution of scientific or technological uncertainty.3

Revenue may require the company to provide additional information, explanations and particulars, and to give any assistance reasonably required to inspect the information in the notification.14

How it is filed

The form must be filed only through MyEnquiries, choosing the category "Corporation Tax (CT)" and the subcategory "R&D Pre-filing Notification".23 When the company later completes Form CT1, it should tick the box on the R&D tax credit panel to show that the notification was submitted.13

A separate form applies to claims under section 766D for buildings and structures.23

What the notification is not

The form states that it is not a claim for the R&D corporation tax credit. The claim is made on Form CT1 within 12 months from the end of the accounting period in which the expenditure was incurred.3

The form does not ask who prepared the notification or the claim, or how any adviser is paid. It is signed on behalf of the company.3 See preparer identification.

Summary

Point	Rule
Legal basis	Section 766C(17), section 766D(16)1
Applies from	Accounting periods beginning on or after 1 January 20241
Who	First-time claimants and companies with no claim in the previous three accounting periods1
When	At least 90 days before the claim is made3
How	Prescribed form through MyEnquiries3

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 (including footnote 4) and section 8.6.1 (including Example 31). 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, Research and Development (R&D) Corporation Tax credit: Pre-filing notification requirement (published 18 July 2025). https://www.revenue.ie/en/companies-and-charities/reliefs-and-exemptions/research-and-development-rd-tax-credit/pre-filing.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 766C, subsections (9) and (17). https://www.revenue.ie/en/tax-professionals/documents/notes-for-guidance/tca/part29.pdf (accessed 11 October 2026). Back