Last updated: 16 October 2026
Why is HMRC asking for additional information on R&D claims?
Since 8 August 2023, every company claiming research and development (R&D) tax relief must submit an Additional Information Form (AIF) to HMRC before or on the same day as its Company Tax Return. If the form is not sent, HMRC removes the R&D claim from the return. HMRC brought this in because of high levels of error and fraud in R&D claims.
What the Additional Information Form asks for
- Company details and a contact, plus the details of any agent who helped prepare the claim
- The name of a senior officer who has approved the claim
- A breakdown of qualifying costs, such as staff, software, consumables and subcontractors
- A description of each project: the scientific or technological advance sought, the uncertainties and how the company tried to overcome them
The R&D schemes for 2026/27
| Scheme | Who it is for | Benefit |
| Merged R&D expenditure credit | Most companies, for periods starting on or after 1 April 2024 | Taxable credit of 20% of qualifying costs |
| Enhanced R&D intensive support (ERIS) | Loss-making SMEs spending at least 30% of total costs on R&D | Extra 86% deduction and a payable credit of up to 14.5% of the surrenderable loss |
The 20% credit is taxable, so its net value is about 15% for a company paying 25% corporation tax and about 16.2% at 19%.
Claim notification
Companies claiming for the first time, or that have not claimed in the previous three years, must send a claim notification within six months of the end of the accounting period. Missing it means the claim is not valid, even if the work qualified.
Example
A software company with a year ending 31 March 2026 spends £200,000 on qualifying staff costs and £20,000 on cloud computing. Under the merged scheme its credit is 20% of £220,000, or £44,000, before tax. It must file the AIF and CT600 by 31 March 2027, and because it is a first-time claimant it needed to send a claim notification by 30 September 2026.
What HMRC checks
HMRC opens many enquiries into R&D claims. It looks for projects that are routine development, costs that are not qualifying, and claims made by advisers paid on large contingent fees. A well-documented claim, with technical narratives written by the people who did the work, stands up best.
What does not qualify
- Work in the arts, humanities or social sciences
- Routine software updates or using existing technology
- Market research, design for appearance only, or general business improvement
- Most overseas subcontracted work, since April 2024
Frequently asked questions
Can I amend an R&D claim?
Yes, within the normal time limit of two years from the end of the accounting period, and a new AIF is needed.
Do I need an R&D specialist?
Not necessarily. Many accountants prepare claims, but the technical detail must come from your team.
Can a sole trader claim R&D relief?
No. It is only for companies.
Is grant funding a problem?
Under the merged scheme, subsidised expenditure no longer reduces the claim as it did under the old SME scheme.
Related: scientific sector relief requirements, patent box benefits and company tax refund timing.
Talk to Accotax
Want this handled for you? Our team at Accotax can help with R&D tax relief claims. See our limited company accountants service, or contact us for a free, no-obligation quote.
This page is general guidance based on HMRC rules for the 2026/27 tax year, checked against gov.uk on 16 October 2026. It is not personal advice, so speak to an accountant about your own situation.
