31 August 2026
Your accountant may seem like the obvious choice for preparing an R&D tax credit claim. But does your claim have the right combination of financial, tax and technical expertise? We look at the risks of underclaiming, overclaiming and whether specialist R&D support should be part of the process.
For many businesses, the obvious person to ask about an R&D tax credit claim is their accountant. It makes sense. They understand your business, prepare your accounts and Corporation Tax return, and already have access to much of the financial information required.
But an R&D tax credit claim isn’t simply about tax. It requires businesses to demonstrate not only what they spent, but what R&D actually took place, why the activities qualify and how the expenditure relates to those activities. And that distinction matters.
They know your finances, do they know your R&D?
Revenue’s requirements effectively create two sides to an R&D tax credit claim:
→ the scientific or technological case and
→ the financial case.
To qualify, activities must be systematic, investigative or experimental; take place in a field of science or technology; seek scientific or technological advancement; and involve resolving scientific or technological uncertainty. That means somebody preparing the claim needs to get underneath the terminology used by the business and understand what its engineers, developers, scientists or technical teams were actually trying to achieve.
A general accountant may be extremely good at tax and accounting without having the specialist technical expertise needed to interrogate an R&D project.
The risk of being too conservative
One of the less obvious risks of using a non-specialist adviser is underclaiming.
A business might identify its most obvious R&D project but overlook qualifying activity taking place elsewhere. Or it may identify the right projects but fail to capture all of the expenditure associated with them. That’s particularly easy when R&D isn’t confined to a formal R&D department.
Innovation can happen within manufacturing, software development, engineering, product development, process improvement and other operational teams. Employees themselves may not describe what they’re doing as “R&D”.
A specialist adviser should know where to look and, importantly, what questions to ask.
The opposite risk: claiming too much
Being overly aggressive creates a different problem. An adviser who doesn’t fully understand the qualifying criteria may include projects because they appear innovative, difficult or technically impressive.
But innovation and R&D are not necessarily the same thing for tax purposes. The question isn’t simply whether something was new to your company. The qualifying activities need to satisfy specific scientific or technological criteria.
A claim therefore needs a defensible boundary between qualifying R&D and routine commercial, engineering, development or implementation activity.
Technical documentation matters
It is tempting to think that once the numbers have been calculated, most of the work is done. In reality, the evidence supporting the R&D can be just as important. Revenue expects companies to maintain records capable of supporting both the scientific and accounting aspects of the claim.
That can include:
A good adviser should help you build the claim around the evidence that already exists within the business, rather than attempting to reconstruct the technical story after the event. You might find that using your accountant significantly increases the amount of time you need to dedicate to the claim.
R&D shouldn’t be a once-a-year conversation
Another potential weakness in the traditional accountant-led approach is timing. If R&D is only discussed when the Corporation Tax return is being prepared, valuable information may already have been lost. People move roles. Projects change. Technical decisions are forgotten. Records become harder to find.
There is also now a pre-filing notification requirement for companies making their first R&D Corporation Tax Credit claim, or those that haven’t claimed during the previous three years. Where it applies, Revenue requires notification at least 90 days before the claim is made.
That makes it increasingly important to think about R&D well before the tax filing deadline.
What happens if Revenue asks questions?
Perhaps the most important question to ask any adviser is: Who will support us if Revenue reviews the claim?
Preparing a claim and defending one require many of the same skills. An adviser should be able to explain the methodology used, substantiate the expenditure and engage confidently with questions about the underlying science or technology.
If specialist technical support would need to be brought in only after Revenue raises questions, it is worth asking whether that expertise should have been involved when the claim was prepared in the first place.
Accountant or R&D specialist? It doesn’t have to be either/or
None of this means businesses should exclude their accountant from the process. Quite the opposite. Your accountant has an important role to play. They understand your financial position, tax affairs and wider business. The strongest approach can often be for the accountant, company and specialist R&D adviser to work together.
X The important question isn’t: “Can my accountant submit my claim?”. They almost certainly can.
✓ A better question is: “Do we have the right combination of tax, financial and scientific or technological expertise to identify, prepare and defend the claim properly?”
For a relief now worth 35% of qualifying R&D expenditure, that’s a question worth asking.
