Tell HMRC that you’re planning to claim Research and Development (R&D) tax relief by making a claim notification
Check when you need to notify HMRC in advance about an R&D Corporation Tax relief claim, the information you will need to provide and how to send it.
When to notify
If you’re planning to claim Research and Development (R&D) tax relief or expenditure credit for accounting periods beginning on or after 1 April 2023, you must submit a claim notification form if:
- you’re claiming for the first time
- your last claim was made more than 3 years before the last date of the claim notification period
You may need to submit a claim notification form for 2 consecutive accounting periods if your previous claim was submitted in the last 6 months of the Company Tax Return amendment window.
These examples will show you when you must submit the claim notification form if you incur R&D costs in either one or two consecutive accounting periods.
Example 1 — when to submit for a 12-month period of account (one accounting period)
If the period of account in which you incur R&D costs runs from 1 January 2024 to 31 December 2024:
- the first day of the accounting period is 1 January 2024
- the end date of the accounting period is 31 December 2024
- submit the claim notification form between 1 January 2024 and 30 June 2025
Example 2 — when to submit for a 15-month period of account (2 accounting periods)
If the period of account in which you incur R&D costs runs from 1 January 2024 to 31 March 2025:
- the start date of the first accounting period is 1 January 2024, and the end date is 31 December 2024
- the start date of the second accounting period is 1 January 2025, and the end date is 31 March 2025
- submit the claim notification form between 1 January 2024 and 30 September 2025
Before you start
Follow these steps to check your understanding of when to submit a claim notification form.
Step 1 — identify your claim notification window
This example will show you how to identify your claim notification window.
A company has a period of account and an accounting period that both run from 1 April 2025 to 31 March 2026. This means the period of account and the accounting period are the same 12-month period.
The company can notify HMRC of its intention to claim R&D tax relief or expenditure credit for this accounting period during the claim notification window.
The claim notification window in this example:
- starts on the first day of the accounting period, in this instance 1 April 2025
- ends 6 months after the end of the period of account in which the accounting period containing the claim falls, in this instance 30 September 2026
Step 2 — check if the 3-year exemption applies
This example will show you how to check if the 3-year exemption applies.
The claim notification window starts on 1 October 2023 and ends on 30 September 2026 (3 years).
A company does not have to submit a claim notification form for the current accounting period, if they made an R&D tax relief claim for an earlier period at any point during the 3 years.
Step 3 — if the 3-year exemption does not apply
There may be circumstances when a relevant claim is made for an earlier accounting period after the last date of the claim notification window for the current period.
This claim would not be considered part of the 3-year exemption, but may be considered as part of the long period of account exemption.
As an example, a company made an R&D tax relief claim for an earlier period on 1 November 2026 (after the normal claim deadline but before the Company Tax Return amendment deadline).
If the company has a long period of account that covers both the earlier period and the current period, then a claim notification for the current period would not be required. This is because the claim notification covers the whole of the period of account and the long period of account exemption applies.
If there is no long period of account, the company would have to submit a new claim notification for their current year claim to be valid.
If you’ve not notified us when you’re required to, and you’ve already submitted your company’s Company Tax Return, we will write to you to confirm that we will remove your claim for R&D tax relief from your Company Tax Return.
If you’ve previously claimed using the paper Company Tax Return, you should submit a claim notification form to avoid any queries or delays when HMRC processes your claim.
Who can notify
You can complete and submit the claim notification form if you’re:
- a representative of the company
- an agent acting on behalf of the company
What information you will need
To complete the claim notification form you will need the following details:
- the company’s Unique Taxpayer Reference (UTR), this must match the one shown in your Company Tax Return
- the main senior internal R&D contact in the company who is responsible for the R&D claim, for example a company director
- the contact details of any agent involved in the R&D claim
- the accounting period start and end date for which you’re claiming the tax relief or expenditure credit, this must match the one shown in your Company Tax Return
- the period of account start and end date
- a summary of the high-level planned activities, for example if you’ve developed software what it will be used for to show that the project meets the standard definition of R&D — you do not need to include evidence on the form, but you will need to provide further information on the additional information form
‘Any agent involved in the R&D claim’ includes:
- all agents who have provided advice in relation to any part of the R&D claim
- agents who have helped prepare all or parts of the claim through technical assessment or analysing costs
- agents who are involved in the making of the claim, including by providing information for or completing the online forms and the filing of the Company Tax Return
If you’re a large business customer
For information on how HMRC deals with expenditure credit claims for large business customers, read CIRD80370 Corporate Intangibles Research and Development Manual.
If you have any questions relating to the claim notification form, you can contact the Large Business Directorate, using the relevant contact us email address and copying in your customer compliance manager.
Submit your form
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You will need to submit using one of the following:
- a Government Gateway user ID and password, if you do not have a user ID, you can create one the first time you sign in
- an email address
You will not be able to access the form once it’s been submitted, so save a copy before you submit it.
You will then get an email to confirm that we’ve received the form. This email will contain a reference number.
Keep a note of this reference number so that:
- you can discuss your claim notification form with HMRC
- if we need to, we can check that you’ve submitted your claim notification form
You do not need to do anything further if you decide not to continue with your claim.
How to claim the R&D tax relief
If you decide to continue with your claim:
- put an ‘X’ in box 656 of the Company Tax Return to tell us that you’ve submitted the claim notification form
- complete the computations for the relevant accounting period
- complete and send us the supplementary form CT600L if you’re claiming payable credit or expenditure credit
Read more information on how to complete the Company Tax Return.
Changes from 8 August 2023
From 8 August 2023 you must submit an additional information form to support all your claims for R&D tax relief or expenditure credit. If you do not submit the additional information form, your claim will be invalid.
Read the guidance which tells you how to send the additional information form and what you will need to provide.
Last updated 10 January 2024 + show all updates
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Clarification added of who needs to submit a claim notification form, the statutory deadline for doing so and which agents involved in the claim need to provide contact details.
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The guidance on when you must notify and when you may need to notify HMRC by submitting a claim notification form has been clarified. A new section 'Before you start' has been added to help you check your understanding of when to submit a claim notification form. The information on when you must submit an additional information form has been updated from 1 August 2023 to 8 August 2023, and the text regarding voluntary submission of the additional information form before the mandatory date has been removed.
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The dates in example 1 and example 2 in the section 'When you must notify by' have been amended to show the correct periods of account and submission dates.
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Added translation