R&D tax claims are under more scrutiny than ever. HMRC compliance checks have increased, reporting standards are tighter, and poor-quality submissions are far more likely to be challenged.
For many businesses, the real issue isn’t eligibility, it’s time. Preparing a compliant R&D tax credit claim requires a detailed technical report, and most finance teams don’t have the internal resource to produce one.
R&D tax claims don’t fail because the work isn’t innovative. They fail because the explanation isn’t clear, detailed, or technical enough.
What actually goes into an R&D tax claim?
Preparing an R&D tax claim isn’t just a finance exercise. It’s a mix of technical analysis, cost modelling, and checking for complete compliance.
An R&D tax claim is made of two parts: the technical justification and the financial justification.
Claims must include an Additional Information Form (AIF) which covers:
- Your company’s details and contact information
- A breakdown of eligible costs, mapped to HMRC categories
- A technical narrative explaining the scientific or technological advance
- Evidence that uncertainty existed and was overcome
To fill out an AIF, many choose to prepare a full cost analysis and a technical report that meets HMRC’s requirements.
The claim is actually submitted with your Company Tax Return (CT600), but it will be rejected without the accompanying AIF.
What is a technical report?
The technical report is a crucial part of your R&D tax credit claim; it contains all the information that proves your projects qualify. In the event of a compliance check, this report is the foundation of your argument.
You’ll need to include:
- The main field of science or technology
- The baseline level of science or technology
- The advance you sought in science or technology
- The scientific or technological uncertainties
- How your project seeks to overcome these uncertainties
Many companies choose to provide additional information beyond the basic requirements of the AIF to better prepare for a potential enquiry. This extra information may include staff credentials, timelines of R&D work, evidence of work undertaken or of the state of the art.
How long does the technical report take?
The short answer is: it depends.
The number of projects and their complexity and depth will impact how long it takes for you to adequately describe your R&D.
For most mid-sized companies with several projects, the technical report can take 10–15 hours of focussed work. For smaller companies with a single R&D project, you may be looking at 2-4 hours of work.
That time isn’t just writing. It includes interviews with your technical team, translating complex work into HMRC-friendly language, mapping projects to qualifying criteria and reviewing drafts for accuracy and risk.
The good news is, if you have over three projects, you’ll only need to prepare narratives for a minimum of 3 three projects that cover 50% of your costs.
You can reduce the time you spend on your claim internally by outsourcing the claim preparation to a specialist, or by using online software tools.
For more information on writing technical reports, read our full guide: Preparing Robust R&D Tax Technical Reports - A Simple Guide
What about the financial analysis?
Finance teams will also need to invest time into a claim for it to pass muster with HMRC.
You can claim for six distinct cost categories: staff costs, subcontractors, externally provided workers, software licenses (including data licenses and cloud computing), consumable items and clinical trial volunteers.
Each of these cost categories needs to be correctly apportioned to each R&D project undertaken. Your team will need to first gather all the costs, then work out how much of each person’s time or invoice, or each items cost actually relates to the R&D project.
Typically, internal time looks like this:
- 2–5 hours gathering cost data
- 3–6 hours analysing and apportioning the costs
- 2–4 hours approving the final submission
That level of internal effort is manageable. What isn’t manageable is expecting finance teams to assess technical uncertainty or explain engineering decisions to HMRC. In practice, that approach often runs into problems.
Proper separation of technical and financial tasks makes the entire claim move more smoothly and results in a more robust claim.
How long does a full claim take end to end?
For an established company with ongoing R&D activity, a full UK R&D tax claim usually takes 4–8 weeks from kick-off to submission.
However, that timeline depends on:
- Number of projects involved
- Quality of existing documentation
- Availability of technical and finance staff
- Claim value and complexity
Larger claims take longer, especially where audit readiness is a priority. Businesses claiming £300k+ often require deeper analysis and more robust evidence.
We’ve seen claims get turned around in a week and we’ve seen months pass by for busy claims. With that said, never attempt to rush a claim as this will only increase your risks. HMRC expects clarity, not speed.
Many claimants choose to speed up their claim timelines by engaging an R&D tax credit specialist. A good R&D tax adviser will lead technical interviews with your team, draft the technical report on your behalf, support your finance team with their analysis, challenge assumptions to reduce risk and handle HMRC queries post-submission. This shifts the workload away from your internal teams while improving audit readiness.
For companies with smaller value or less complex claims, software solutions like Tax Cloud offer a compromise. Using an online portal allows you to take more control over your claim with our guided questions and you can be sure of its compliance thanks to reviews from our expert team.
For more information on your options when outsourcing your claim, check out our full guide: Should I Use a Consultant, Software, Or DIY My R&D Tax Credit Claim?
Key takeaways
- The technical report is the most time-consuming part of an R&D tax claim
- Expect 10–15 hours of technical input for a compliant narrative and 7-15 hours of finance analysis
- End-to-end claims typically take 4–8 weeks
- Poor claim reports increase HMRC scrutiny and delay repayments
If preparing your R&D tax credit claim feels like a risk (or a drain on your team’s time), R&D tax advisers can help. Get in touch with our experts for a free, no-obligation discussion of your projects.
