It depends on the claim, and anyone who answers this question without asking about your claim is selling something. Your accountant and a specialist are both legitimate routes; they are good at different parts of the work, and the honest comparison starts with what the work actually is. We are a specialist firm, so read this knowing where we sit — but the cases below where your accountant is the right answer are real, and we say so to clients.
What preparing a claim actually involves
An R&D claim is two jobs joined in the middle. One is tax mechanics: the computation, the CT600, the scheme rules, the rates. The other is a technical case: identifying which projects meet the statutory definition of R&D, drawing out a competent professional’s account of the uncertainties, and writing the Additional Information Form so it stands up to a reader whose job is scepticism. Around both sit the compliance gates — claim notification for newer claimants, the AIF for everyone — and behind them the possibility of an enquiry, which HMRC opened on around one in six claims in 2023-24.
General practice covers the first job well. The second is where claims are won and lost, and it is a genuine specialism: not because accountants lack ability, but because applying the R&D definition across sectors, and defending that application to HMRC, is volume work that a general practice sees a few times a year and a specialist sees every week.
When your accountant is the right answer
- The claim is small and the facts are simple. One clearly qualifying project, good records, modest value: a specialist’s fee may not be worth the increment, and an honest specialist will tell you so.
- Your accountant genuinely knows the relief. Some firms have real R&D capability. The test is not willingness but practice: ask how many claims they prepare a year, and how many have been through an enquiry.
- Continuity matters more than optimisation. Your accountant knows your numbers, your payroll and your history. For a steady, repeat claim with no changes in the rules or the business, that context has real value.
When a specialist earns the fee
- First claims. The notification window, the AIF’s technical demands and the definition itself arrive all at once, and the six-month notification deadline forgives nothing. Most of the invalid claims HMRC removes were not dishonest; they were prepared by someone who did not know a rule existed.
- The technical boundary is genuinely unclear. Software, process development, work that shades between routine and qualifying: the cases where the definition needs applying carefully are the cases where applying it carelessly gets expensive.
- The structure is complicated. Contracted-out R&D, grants, connected companies, overseas elements, ERIS intensity near the threshold: each is a place where the right answer changes with the facts.
- The claim is material to the business. When the credit is a meaningful part of your cash flow, the cost of getting it wrong, or of under-claiming, outgrows the fee.
- There is an enquiry. Defence is specialist work in any profession. This is also the moment you learn what your original adviser’s work was worth.
The third option, which is usually ours
Most of our clients keep their accountant. The accountant runs the accounts, payroll and the wider tax relationship; we prepare the R&D claim, the technical narrative and the AIF — and we prefer to submit the return containing the claim ourselves, or amend it if it has already been filed, because the firm that prepared a claim should be willing to put its own name on the submission and stand behind it with HMRC. Where a client’s accountant prefers to do the filing, we hand over reconciled figures and remain named on the claim either way: every agent involved must now be declared on the AIF, so there is no version of this arrangement in which the preparer is invisible — and be wary of any adviser who wants to be. Nobody is displaced, and each does the work they are best placed to do; the arrangement is set out on working with accountants. If you are an accountant reading this, that page is written for you.
How to decide
Ask whoever will prepare the claim, accountant or specialist, the same questions: who applies the R&D definition and what is their basis for it; who speaks to the technical staff; who writes the AIF; what happens in an enquiry and at what cost; and will they say so if part of the claim does not qualify. The answers matter more than the label on the firm. The verifiable checks, registers, conduct rules, insurance, are on how to choose an R&D tax adviser.
If you want a view on your own claim, either the one you are planning or the one someone else filed, a free claim review or a first conversation costs nothing, and if the honest answer is that your accountant has it covered, that is the answer you will get.
Written by Matthew Jones ACA CTA. Last reviewed July 2026.
Sources
- Check if a project qualifies as R&D for tax purposes — the definition the technical case rests on.
- Submit detailed information before you claim — the AIF every claim now requires.
- Tell HMRC you plan to claim — the notification gate that catches first-time claimants.