United Kingdom: Claim notification | Research Credit Integrity Alliance

This page explains the claim notification: the advance notice some companies must give HMRC before they can claim United Kingdom research and development (R&D) tax relief. It describes the rules only and makes no recommendation.

Legal basis

The requirement is in the Corporation Tax Act 2009. Sections 1042C and 1045A prevent a claim to the merged R&D expenditure credit (RDEC) and to enhanced R&D intensive support (ERIS) respectively from being made after the end of the claim notification period, unless one of the conditions described below applies. Section 104AA operates in a similar way for the earlier RDEC scheme.1 The ERIS provision applies to claims for accounting periods beginning on or after 1 April 2023, including claims under the earlier SME scheme. The merged RDEC provision applies to accounting periods beginning on or after 1 April 2024.1

Section 1142A defines the claim notification period and allows HMRC to specify by regulations what a notification must contain and how it is made. The content is set out in Schedule 1 to the Relief for Research and Development (Content of Claim Notifications, Additional Information Requirements and Miscellaneous Amendments) Regulations 2023 (SI 2023/813).1

HMRC lists advance notification of claims among its policy changes to address error and fraud, applying to accounting periods from April 2023.2

Who must notify

HMRC's manual states that a claim cannot be made after the end of the claim notification period unless at least one of the following applies:1

Condition	Effect
The company made an R&D claim in the three years ending with the last day of the claim notification period	No notification needed. A claim for an accounting period beginning before 1 April 2023, made in an amendment submitted on or after 1 April 2023, is ignored for this purpose
The company makes a claim notification within the claim notification period	The claim may be made after the end of the claim notification period
The accounting period falls within the same period of account as another accounting period for which the company has made an R&D claim or claim notification	No further notification needed

HMRC's guidance puts this more simply. A company must submit a claim notification form if it is claiming for the first time, or if its last claim was made more than three years before the last date of its claim notification period.3 A company that claimed within that three year window must still notify if HMRC rejected its earlier claim by removing it from the Company Tax Return, or if the earlier claim was for an accounting period beginning before 1 April 2023 and was made by an amendment received on or after 1 April 2023.3

A company that needs to notify can instead make the R&D claim itself, in its Company Tax Return or an amendment, so that HMRC receives it by the last date of the claim notification period.3

The claim notification period

The period begins on the first day of the period of account and ends six months after the end of the period of account.13 The period of account is the period covered by the financial statements, which may be longer than 12 months. An accounting period, covered by the Company Tax Return, cannot be longer than 12 months.3 Where a period of account contains two or more accounting periods, the claim notification period is the same for all of them, and a first time claimant needs to submit the form for only one of those accounting periods.3

HMRC gives these examples:3

Period of account	First date of claim notification period	Last date of claim notification period
1 January 2024 to 31 December 2024	1 January 2024	30 June 2025
1 January 2024 to 30 June 2025 (two accounting periods)	1 January 2024	31 December 2025

What the notification contains

Schedule 1 to SI 2023/813 specifies the information:1

Subject	Information
The company	Registered name and Unique Taxpayer Reference
The company officer responsible for the accuracy of the information	Name, role in the company, telephone number and email address
Each agent or tax adviser	Name, or registered number if a registered company; agent reference number; business or trading name; address of principal place of business; email address; telephone number; and role (acting on the R&D claim only, or on the R&D claim and other tax matters)
The R&D claim	Start and end dates of the accounting period and the period of account; the number of R&D projects; and an overview of the projects for the period of account

HMRC's guidance asks for the contact details of all agents involved in the claim, including any agent who has given advice, analyzed costs, helped prepare technical assessments, or given information for or completed the online forms or the Company Tax Return.3 The summary of planned activities should be high level. Evidence is not needed on the notification, because more detail is required later on the additional information form.3 See Additional Information Form and Preparer identification.

How it is made

A claim notification must be made through HMRC's online service.1 It can be completed by a representative of the company or by an agent acting for the company.3 The person signing in uses a Government Gateway user ID or a confirmation code sent by email. HMRC sends an email confirming receipt with a reference number, and the form cannot be accessed again once submitted.3 A company that decides not to go ahead with its claim after notifying does not need to do anything further.3

Consequences of missing the deadline

If a required notification is not made within the claim notification period, the R&D claim is invalid.3 HMRC's manual sets out one administrative easement. It records that incorrect guidance on the three year condition was published between 8 September 2024 and 17 October 2024, and that HMRC will allow claims without a notification for companies that meet the stated conditions and apply to its R&D Policy team. The easement does not affect a company's statutory filing obligations, including the time limit for making a claim.1 See Disputes and appeals.

What the notification does not ask

Neither Schedule 1, as reproduced in HMRC's manual, nor HMRC's guidance asks how an agent is paid or whether its fee depends on the amount of the claim.13

Sources

HM Revenue and Customs, Corporate Intangibles Research and Development Manual, CIRD183000, "R&D Tax Reliefs: reformed reliefs: claims process: pre-notification of claims" (manual updated 25 August 2026), sections "Statutory framework", "Administrative Easement", "Claim notification period", "How a claim notification is made" and "Information to be provided". https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird183000 (accessed 11 October 2026). Back
HM Revenue and Customs, Approach to Research and Development tax reliefs 2023 to 2024 (published 30 October 2024), section 2.1, Table 2. 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). Back
HM 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: claim notification period", "Working out your claim notification period", "What information you'll need", "Submit your form", "What to expect after you've submitted" and "What you need to do next". https://www.gov.uk/guidance/tell-hmrc-that-youre-planning-to-claim-research-and-development-rd-tax-relief (accessed 11 October 2026). Back