What is a claim notification (and why does it exist)?
A claim notification (often called “advance notification”) is a procedural requirement introduced to make HMRC aware you plan to claim R&D tax relief for a particular accounting period before you file the claim in your Corporation Tax return.
It does not approve your claim, and it does not replace the work needed to prepare a compliant submission. It’s simply an eligibility gateway for certain businesses.
When do you need to notify HMRC in advance?
This requirement applies to claims relating to accounting periods that begin on or after 1 April 2023.
If you’re a regular claimant, you often won’t need to submit a claim notification for every period. The trigger is about your claim history.
Step 1: Check whether you need to submit a claim notification form
You will usually need to submit a claim notification form if either:
- This is your first R&D claim, or
- Your last relevant R&D claim was made more than 3 years ago (measured against the end of your claim notification period).
If you’ve claimed within the relevant window, you’ll usually be outside the notification requirement (but still need to meet all the other R&D claim requirements).
Step 2: Work out your deadline (the “claim notification period”)
The claim notification period:
- starts on the first day of your accounting period, and
- ends 6 months after the end of that accounting period.
For a standard 12-month year, that’s typically an 18-month window.
Example
If your accounting period runs from 1 October 2023 to 30 September 2024, your claim notification period runs from 1 October 2023 to 31 March 2025.
Step 3: Submit the claim notification form
You submit the claim notification form through HMRC’s online process. It asks for core company and period details plus a high-level description of the R&D you intend to claim for.
Important: you don’t need to provide full technical evidence at this stage — but your summary should still be consistent with what you later submit in the claim narrative and costs.
What information do you need to provide?
In practice, you’ll be asked for details such as:
- your company’s UTR
- the start and end dates of the accounting period you plan to claim for
- a named senior person in the business responsible for the claim
- agent/adviser details (if you use one)
- a short, high-level overview of the planned R&D activities.
Step 4: Don’t confuse claim notification with the additional information form
These are different steps and both can matter:
- Claim notification form: only required for certain claimants, and must be submitted within the claim notification period.
- Additional information form (AIF): must be submitted as part of the claim process (separately, via HMRC’s portal).
Think of claim notification as “permission to enter the room”, and the AIF + CT600 as “the work you present once you’re inside”.
Common mistakes that trigger avoidable problems
- Tracking the CT600 filing deadline instead of the claim notification deadline (they’re not the same)
- Assuming you need to notify every year (many regular claimants don’t)
- Mixing up the two forms (claim notification vs AIF)
- Leaving it late when you’re unsure, the rules are time-bound and missing them can invalidate the claim
Claim notification - FAQs
Does the merged R&D scheme change this requirement?
No, claim notification is a claims-process requirement and can still apply regardless of whether your claim sits under the merged scheme or other routes. (Your scheme affects how relief is calculated, not whether procedural steps apply.)
What happens if I miss the claim notification deadline?
If you were required to notify and didn’t, HMRC can treat the claim as invalid for that accounting period.
Do I need evidence when I notify?
Not usually at the notification stage, it’s intended to be high-level. Evidence and detail come later with the claim itself.
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