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additional information form r&d

Essential Guide to the R&D Additional Information Form for Small Businesses

October 8, 2025 by Lera Accountancy
Contents hide
What Is an R&D Claim Notification?
Why It Matters for Your Business
When Is Advance Notification Required?
How to Notify HMRC
How We Can Help
FAQs
What is the new claim notification form?
Who must submit the new claim notification form?
When to submit the new claim notification form?
What is the additional information form for R&D claims?
What information should be provided on the additional information form for R&D claims?

What Is an R&D Claim Notification?

An R&D claim notification is a formal process that ensures your company retains the right to submit a claim for Research and Development (R&D) tax credits.

This requirement applies when a business is making a claim for the first time, or when there has been a break in claiming for a specified period.

The purpose of the notification is to alert HMRC of your intention to claim R&D relief for a given accounting period, confirming your eligibility to do so.

Why It Matters for Your Business

Submitting the notification is crucial. If you are required to notify HMRC but fail to do so, any subsequent R&D claim will be automatically rejected, regardless of its validity.

The rules surrounding R&D claims are intricate and can easily catch businesses unaware, especially when accounting periods are shortened or lengthened, or when corporate restructuring occurs.

This can be particularly problematic for groups acquiring new subsidiaries that have not previously claimed R&D relief, or for cases where trading divisions are transferred into new entities. In such situations, it’s easy to overlook the need for a fresh claim notification.

Additionally, businesses must ensure that they accurately report the number of qualifying R&D projects. HMRC enforces strict requirements in this area, and any omissions or inaccuracies can cause delays or jeopardize a claim.

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When Is Advance Notification Required?

The advance notification requirement applies to accounting periods that begin on or after 1 April 2023. Your company must notify HMRC of its intention to claim R&D relief either during the relevant accounting period or no later than six months after its end.

For instance, if your company plans to make a first time claim for the financial year ending 30 June 2024, you must notify HMRC between 1 July 2023 and 31 December 2024.

However, the rule does not apply if you have already made regular claims within normal filing deadlines.

Continuing the example above, if your business made an R&D claim for any valid accounting period that falls within the three years preceding the end of the notification window (in this case, between 1 January 2022 and 31 December 2024), no additional notification would be necessary unless that earlier claim was struck out following an HMRC enquiry.

A key point to note is that the phrase “normal filing deadlines” excludes any amended corporation tax returns submitted after 1 April 2023 for accounting periods that started before that date. Such late amendments are disregarded for the purpose of determining whether the company is considered an ongoing claimant.

R&D claims are made on a company by company basis, meaning that each entity within a group may need to submit its own separate notification.

Furthermore, the six-month notification window is fixed relative to the end of the accounting period. If your company’s accounting period is shortened (for instance, due to a takeover or restructuring), this effectively shortens the time available to notify HMRC.

How to Notify HMRC

To notify HMRC, you must complete a standalone online form. This form requests key identification details such as your company registration number, VAT number, PAYE reference, and SIC code.

It also asks for practical information, including the name of any agent or adviser assisting with the R&D claim, and the name of a responsible company officer typically the R&D or finance director who authorizes the submission.

The form also requires a summary of the high level planned R&D activities. While this is far less detailed than the “Additional Information Form” required when submitting an actual R&D claim, it must still explain why you believe the project qualifies as R&D and specify the number of projects involved.

Accuracy and clarity at this stage will help ensure a smoother process when the full claim is later reviewed.

How We Can Help

Our specialist R&D team works closely with your technical and finance teams to evaluate your projects and determine whether they qualify for R&D tax credits. We assist in compiling, testing, and validating all relevant cost data, ensuring your claim is accurate, compliant, and optimized for success.

We also handle the preparation and submission of all required HMRC forms including the claim notification so you can focus on innovation while we manage the compliance process. Get in touch with our team for expert guidance on preparing and submitting your R&D claims efficiently and effectively.

FAQs

What is the new claim notification form?

The Claim Notification Form notifies HMRC in advance that your company plans to submit an R&D tax relief or R&D expenditure credit claim for an accounting period starting on or after 1 April 2023.

Who must submit the new claim notification form?

You must submit the form if:

  • You are claiming R&D tax relief for the first time, or

  • You haven’t made an R&D claim in the past three years, counted from the end of your last claim notification period.

When to submit the new claim notification form?

The claim notification period covers:

  • From: the first day of your accounting period

  • To: six months after the end of that period

For accounting periods of 12 months or less, the notification period typically aligns with your accounting period.

If your period exceeds 12 months, it may span multiple accounting periods, but only one notification is required.

Missing the notification deadline will make your R&D tax credit claim invalid.

What is the additional information form for R&D claims?

Since 1 August 2023, HMRC requires all companies making an R&D claim to submit an additional information form before filing their Corporation Tax return (CT600). Failure to submit it will result in your claim being automatically rejected.

What information should be provided on the additional information form for R&D claims?

The additional information form is a detailed form that must be completed carefully. It includes:

  • Company details: name, UTR, and accounting periods

  • Scheme type: SME, RDEC, or Merged scheme

  • Contact details: main internal R&D contact and any advisers/agents

  • Project summaries: up to 10 projects covering at least 50% of total R&D spend, including:

    • The advance sought

    • The scientific or technological uncertainty encountered

    • How you attempted to resolve it

    • Why the solution was not obvious

    • The work carried out

    • A breakdown of qualifying expenditure

 

Read more

Find more articles about Running a small business, Starting a small business, Tax, or below.  
Previous Post:Everything small businesses should know about the Merged R&D scheme
Next Post:Research and Development Expenditure Credit (RDEC) Explainedr&d expenditure credit

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