The R&D pre-filing notification: who files it, and when

If your company is claiming the Irish R&D tax credit for the first time, or has not claimed it in any of the previous three accounting periods, it must notify Revenue before it claims. The pre-filing notification goes in through MyEnquiries at least 90 days before the claim is made on the CT1, and it is not itself a claim.

Who has to file

Section 8.6.1 of Revenue's R&D tax credit manual (Tax and Duty Manual Part 29-02-03) sets the rule, which applies to accounting periods beginning on or after 1 January 2024 (footnote 4). The notification applies to “companies which are claiming the R&D tax credit for the first time, and companies which have not claimed the R&D tax credit in any of the previous three accounting periods”.

There are two forms: one for a claim under section 766C, the credit on R&D expenditure, and one for a claim under section 766D, for a building or structure used for R&D. Each counts previous claims of its own kind.

For the section 766C notification, a claim under the old section 766 counts as a previous claim. In the words of Revenue's form, it “shall not apply where the company has made an R&D claim under section 766 or section 766C TCA 1997 in respect of any of the three immediately preceding accounting periods”. The section 766D form counts only claims under section 766A or section 766D, so a first claim for a building needs its own notification even if the company has claimed the credit on its expenditure.

The 90-day rule

The notification “must be in writing in the form prescribed by Revenue and must be filed at least 90 days before the claim for the credit is made” (section 8.6.1). The 90 days count back from the day the claim is made, not from the end of the accounting period.

Revenue's own example: a company whose accounting period ended on 31 December 2026, and which intends to claim on its CT1 on 31 March 2027, should file the notification on or before 31 December 2026 (Example no. 31).

The claim has its own deadline. It is made on the CT1 within 12 months of the end of the accounting period in which the expenditure was incurred (section 2.6; for a building, the date the expenditure is treated as incurred, section 5.1). The date you plan to claim therefore sets the latest date for the notification, so plan the two together.

What the form asks for

The section 766C form has three sections and a declaration signed on behalf of the company.

• Section 1, the numbers. The number of employees carrying on R&D activities, “as known at the time of completing the pre-filing notification form”; the number of R&D projects, for which Revenue accepts an estimate if the count is not yet final; and any expenditure met directly or indirectly by grant or other assistance.
• Section 2, the description. A brief synopsis of the R&D carried out. Where several projects are involved, it “should give an understanding of what R&D activities were undertaken by the company as a whole”, with examples of the projects. The activities must be qualifying R&D, and the form restates the five conditions: systematic, investigative or experimental activities, in a field of science or technology, that are basic research, applied research or experimental development, seek scientific or technological advancement, and involve resolving scientific or technological uncertainty.
• Section 3, anything else the company considers relevant to the first two sections.

For a building under section 766D, the details are different: confirmation that the building qualifies, the proportion of it to be used for R&D over the four-year specified relevant period, and any grant-funded expenditure (sections 8.6.1 and 5.1). In either case, Revenue may ask for “additional information, explanations and particulars” about what you have filed (section 8.6.1).

How to file it

Through MyEnquiries, under Category “Corporation Tax (CT)” and Subcategory “R&D Pre-filing Notification”. When the claim is made, tick the box on the Research and Development Tax Credit panel of the CT1 to show that the notification has been submitted (section 8.6.1).

What it is not

Revenue prints this under the form's title: “The pre-filing notification form is not a claim for the R&D corporation tax credit.” The claim comes later, on the CT1.

Nor does any supporting R&D documentation have to be submitted with the CT1. Revenue can request it afterwards to verify the claim (section 8.6.2). Our guide to Revenue's R&D tax credit file layout covers what Revenue suggests you keep, project by project.