Avoid Rejection: How to Complete the Additional Information Form for R&D Tax Relief
If your company is claiming R&D tax relief, there is a crucial step you cannot afford to overlook: the Additional Information Form (AIF). Since August 2023, submitting the AIF has been a mandatory part of the R&D tax relief claim process, whether you are applying under the SME scheme, the RDEC scheme, the new merged scheme, or the enhanced R&D intensive support (ERIS) scheme.
Yet many businesses are still uncertain about what the Additional Information Form involves. In this article, we explain its purpose, highlight how to avoid common mistakes for a compliant and smooth submission.
What is the Additional Information Form?
The Additional Information Form is an online form that must be submitted to HMRC before filing your Company Tax Return (CT600) if you are claiming R&D tax relief.
It asks for detailed information about your company, your R&D projects, and the associated costs. HMRC introduced the AIF to strengthen upfront risk assessment and ensure taxpayer money is directed towards genuine innovation.
If you fail to submit the AIF correctly and on time, HMRC will automatically reject your R&D tax relief claim.
Why the AIF is Important
Submitting the AIF is a crucial part of securing your R&D tax relief. It allows HMRC to:
Verify that your R&D activities meet the eligibility criteria.
Confirm your costs and corporate structure.
Check for errors or fraudulent claims before processing your tax return.
If you do not submit the AIF before your CT600, your R&D claim will be removed. Missing this step could result in missing out on your entitlement altogether.
Common Pitfalls to Avoid When Completing the AIF
Here are the most common mistakes businesses make with the Additional Information Form:
1. Submitting the CT600 before the AIF
The AIF must always be submitted first. If both are submitted on the same day, the AIF must be sent first.
2. Using the wrong login credentials
Companies should use their Corporation Tax Government Gateway ID. Agents acting on behalf of companies must use their dedicated agent services account.
3. Missing or incomplete project descriptions
Project narratives must clearly explain the baseline knowledge, the scientific or technological advance, the uncertainties faced, and how these were overcome.
4. Financial inconsistencies
Figures entered in the AIF must match those in the CT600 exactly. Even small discrepancies can cause HMRC to reject the claim.
5. Forgetting to save a copy of the submitted AIF
Once submitted, the form cannot be accessed again via the HMRC portal. Always download and save a copy.
How Many Project Descriptions Are Required?
The number of project descriptions you must include depends on the number of R&D projects you are claiming for and the proportion of total qualifying expenditure they represent.
· 1–3 projects, you need to describe them all.
· 4–10 projects, you need to describe at least 3, covering at least 50% of total qualifying costs.
· 11+ projects, you need to cover at least 50% of total qualifying costs, describing minimum 3 and maximum 10 projects.
This ensures that HMRC can gain a meaningful understanding of the R&D activities that underpin the claim.
Practical Tips for Completing the AIF Correctly
Focus on these AIF-specific actions to stay compliant:
Submit early. Do not wait until the CT600 deadline. Leave enough time to gather and review all required information.
Use the correct portal login. Submit the AIF using your company’s Corporation Tax Government Gateway account.
Prepare clear project narratives. Keep the language straightforward. Explain the technical challenges without unnecessary jargon.
Check financial figures carefully. Ensure totals for qualifying expenditure match exactly between the AIF and the CT600.
Address overseas costs properly. From accounting periods starting on or after 1 April 2024, companies must disclose detailed information about overseas subcontractors and externally provided workers, following the new restrictions introduced by HMRC in September 2024.
Retain proof of submission. Save a PDF copy of the AIF and keep the confirmation reference number from HMRC.
Recent Updates to the AIF: What You Need to Know
In September 2024, HMRC updated the AIF to reflect the new merged scheme and ERIS scheme.
The main changes include:
Companies must specify whether the accounting period began before or after 1 April 2024.
Companies registered in Northern Ireland must provide additional information.
For overseas costs, claimants must:
Identify overseas expenditure separately.
Justify why any overseas costs are eligible.
Provide details of the top ten contractors contributing to qualifying R&D activities.
These updates apply to claims relating to accounting periods beginning on or after 1 April 2024.
Supplementary Reports: Going Beyond the AIF
While submitting the AIF is mandatory, companies can also submit a separate, detailed R&D report alongside it.
At Apogee, we always prepare a comprehensive technical report for every claim. Our report:
Explains clearly why each project qualifies under HMRC’s eligibility criteria and legislation.
Breaks down the costs included in the claim, providing clarity for HMRC reviewers.
Strengthens the claim by giving additional technical context that is not always possible within the limited structure of the AIF.
This extra step helps reduce the risk of compliance checks, delays, or questions from HMRC.
What Happens if You Get It Wrong?
If you submit your CT600 before your AIF, or if your AIF is missing or inaccurate, HMRC will reject your R&D tax relief claim.
You may receive a correction notice, and if this occurs close to the two-year statutory deadline, you could lose your ability to claim altogether.
How Apogee Can Support You
At Apogee, we help innovative companies successfully claim R&D tax relief with full confidence. When you work with us, we:
Prepare and submit your Additional Information Form correctly, ensuring full compliance with HMRC requirements.
Work closely with your technical and finance teams to prepare strong project narratives.
Include all eligible costs - nothing more, nothing less, ensuring your claim is robust and defensible.
Our expertise ensures that your R&D tax relief claim is accurate, compliant, and well-supported.
Final Thoughts
The Additional Information Form is now a fundamental part of the R&D tax relief process in the UK. Without it, your claim will not be accepted.
By understanding the AIF requirements, staying compliant with the latest updates, and working with experienced specialists like Apogee, you can secure the relief your innovation deserves without unnecessary risks.
Need help managing your AIF and R&D tax relief claim?
Get in touch with Apogee today. We are ready to make the process clear, compliant, and efficient.