How Many Technical Reports Do I Need For My R&D Claim?

Updated June 2025

R&D tax credits are an opportunity for companies to claim back some of the costs of risky research and development. Many companies are carrying out R&D without even knowing it; your project just needs to advance the field of science or technology and seek to overcome scientific or technological uncertainty to do it – pretty easy, right?

Once you’re certain you have a qualifying project (feel free to get in touch to confirm your project’s eligibility!), then you can start preparing your technical report.

But how many projects do you need to prepare? How much detail is required? And where does this technical report even go?

To make your R&D tax credit claim, you’ll need to submit an Additional Information Form to HMRC before your claim to demonstrate that your projects are truly qualifying. This includes writing up project details and gathering costing information for the claim’s value.

Before the AIF was mandatory, many companies chose to send these details to HMRC anyway in what is often called a ‘technical report’ – in fact, many companies still send a technical report with extra details to HMRC to pre-empt any questions from a compliance check.

A technical report is a document that contains the same information as an Additional Information Form, plus a bit more to ensure that the claim meets all requirements of the scheme.

Extra details include the qualifications and experience of the competent professionals of a project, project background and examples of evidence that could be provided, as well as images and tables if necessary.

HMRC has specific requirements for the number of projects you need to detail in your AIF. There is a minimum number, but HMRC recognises that companies with many projects may not have the time or resources to write up all the details for every project.

Therefore, HMRC set rules for the number of projects that need write ups:

• For companies claiming 1 to 3 R&D projects, all your projects need to be written up.
• For companies claiming 4 to 10 R&D projects, a minimum of 3 projects must be written up, so long as these three account for at least 50% of the costs being claimed.
• For companies claiming more than 10 projects, the 10 largest projects need to be written up.

These rules are set for the AIF but are also largely followed when it comes to providing a technical report, as no one wants to spend weeks writing up project after project!

How long is a piece of string? Every project is different and may require more or less detail to effectively convey the R&D work carried out. You’re trying to ensure that the HMRC’s reviewer fully understands the work you’ve done, how it advances the field of science or technology, and why it was challenging to carry out.

Companies using Tax Cloud will know there is a character limit to guide the writing process. Within our 2,000-character limit for each question, it should be possible to fully explain your R&D without going overboard. However, claimants should also be wary of writing too little, especially when describing the work done in the period. The narrative must be expanded enough to make it clear what you’ve been doing throughout the accounting period.

Many claimants fall into the trap of providing unnecessary information and focusing too little on the actual work done. Bluntly, HMRC does not care about the commercial successes of your project – you should be entirely focused on the scientific or technological advances you were working on. It may also be easy to wax lyrical about your innovation, but HMRC will look just as closely at the uncertainties and your attempts to overcome them.

However, always be aware that your eventual audience will not be an expert in your field. Try to stick to layman’s terms and avoid including any specifics of the project (e.g., actual code or project results) that may be more confusing than helpful to a non-expert.

You must submit your AIF to HMRC before you submit your actual claim via your Corporation Tax return. This can be months in advance, or mere hours, but the AIF must go first. It’s submitted through HMRC’s dedicated portal.

The AIF will largely contain a lot of the information from your technical report, so it’s best practice to write your technical report first and take the information you need for the AIF from that.

Those that submit a full technical report will send it to HMRC via email when making their actual submission with your Corporation Tax Return.

At Tax Cloud, we take care of the submission, from Advance Notification Form to CT600.

Knowing the what, why and when is what we do at Tax Cloud. You just need to answer our questions and follow our guidance to make your claim.

At a fraction of the price of a boutique consultancy, Tax Cloud helps you prepare robust claims that fully respond to all requirements. With our zero-risk guarantee, you can rest easy knowing your claim is as strong as it can be, while doing minimal work to get your result.

Get in touch with our team to find out more.

Author Barrie Dowsett, ACMA, GCMA CEO, Tax Cloud