R&D Tax Relief for Limited Companies

R&D tax claims fell by more than a quarter in a single year — not because British companies suddenly stopped innovating, but because HMRC tightened the rules around who can claim, and how carefully a claim needs to be built. It's a telling number. R&D relief hasn't gone away, and it certainly hasn't become less valuable. It's simply become far less forgiving of a vague, thrown-together claim.

I still meet directors who tell me, quite confidently, that their business "doesn't really do R&D" — usually running a manufacturing firm, a software company, or a specialist trades business that's spent months quietly solving a genuinely difficult technical problem without ever framing it that way. The bar for qualifying is lower than most people assume, and considerably more generous than the popular image of scientists in white coats suggests. This guide walks through exactly what qualifies, what the relief is actually worth for 2026/27, and — increasingly important — exactly what the paperwork now demands.

What Qualifies as R&D?

The Core Test — Resolving Genuine Technical Uncertainty

HMRC's test is whether your project sought an advance in science or technology by resolving a technical uncertainty that a competent professional in the field couldn't have readily worked out in advance. That's a deliberately specific bar — not "we built something new," but "we didn't know if or how this could be done, and finding out took genuine technical effort."

It's Not Just Labs and Software

The stereotype of R&D as something that only happens in pharmaceutical labs or tech startups is genuinely misleading. I've worked with manufacturers developing a new production process, food businesses reformulating a product to remove an ingredient while keeping shelf life and taste intact, and engineering firms solving a structural problem nobody in the industry had quite cracked the same way before. None of them thought of what they were doing as "R&D" until someone actually asked the right questions.

What Doesn't Qualify

Routine, straightforward development work doesn't qualify, however much effort it took — building a website using established techniques, applying existing, well-understood methods to a new client, or simply following a supplier's instructions to implement something already proven elsewhere. The uncertainty has to be genuinely technical, not just about cost, timescale, or which existing solution to pick.

R&D Tax Relief 2026/27

One Scheme for (Almost) Everyone Now

For accounting periods beginning on or after 1 April 2024, the previously separate SME scheme and RDEC scheme were merged into a single framework, and that merged scheme remains the primary route for most claims in 2026/27. If you claimed R&D relief before that change, the calculations, rates and rules you're used to may look noticeably different under the current system.

Why the Rules Changed

The reform was driven largely by concern over the old SME scheme's vulnerability to abuse — a wave of aggressive, sometimes fraudulent claims eroded confidence in the system and cost the Exchequer significantly. The merged scheme, alongside tighter reporting requirements covered later in this guide, was designed to bring far more scrutiny and consistency to claims going forward.

What Stayed the Same

The underlying qualifying test — genuine technical uncertainty, resolved through real technical effort — hasn't changed. What's changed is the calculation of the relief itself, and considerably more of the compliance burden sitting upfront, before a claim is even submitted, rather than only at enquiry stage afterwards.

The Merged R&D Scheme

How It Replaced the Old SME and RDEC Schemes

The merged scheme broadly follows the mechanics of the old RDEC regime rather than the old SME scheme — an above-the-line taxable credit calculated directly on qualifying expenditure, rather than an enhanced deduction reducing taxable profit before tax is applied.

Who Can Claim Under It

Almost every company undertaking qualifying R&D now claims through this single route, profitable or loss-making, regardless of size — with one significant exception, covered in the next section, for loss-making, R&D-intensive small and medium companies who can access a more generous alternative.

Contracted-Out R&D — Who Actually Claims

If R&D work is commissioned by one company from another, the rules generally allocate the claim to the company that decided to undertake the R&D and bore the risk of it — typically the customer commissioning the work, not the contractor carrying it out. This is a meaningful shift from the pre-2024 rules, and it's caught out more than a few subcontracting businesses who assumed, wrongly, that undertaking the technical work automatically entitled them to claim.

R&D Expenditure Credit – 20%

How the Credit Is Calculated

The merged scheme delivers a taxable credit worth 20% of your qualifying R&D expenditure, recognised above the line in your accounts — meaning it shows up as income, visible in your company's profit and loss account, rather than sitting hidden inside a tax computation.

The Net Benefit After Tax

Because the credit itself is taxable, the actual cash benefit ends up lower than the headline 20% once corporation tax is applied to it. For a company on the main 25% rate, that works out at roughly 15% net benefit on qualifying spend. For a company on the 19% small profits rate, it's slightly better, at roughly 16.2%. Either way, it's a genuinely valuable reduction on real R&D spend — just worth understanding in net, not headline, terms when you're forecasting the actual cash impact.

How Loss-Making Companies Receive It

If your company is loss-making, the credit can still generate a cash payment from HMRC rather than simply reducing a tax bill you weren't going to pay anyway — subject to a cap based broadly on your PAYE and National Insurance liabilities, which stops the relief being claimed disproportionately by companies with very little UK payroll.

Enhanced R&D Intensive Support

The 30% Intensity Test

If your company is loss-making, and your qualifying R&D expenditure represents at least 30% of your total expenditure for the period, you may qualify for Enhanced R&D Intensive Support — ERIS — instead of the standard merged scheme, and it's considerably more generous where it applies.

The 86% Additional Deduction and 14.5% Payable Credit

Under ERIS, qualifying R&D costs attract an 86% additional deduction on top of the expenditure itself — effectively relieving 186% of the qualifying spend against taxable profit — and the resulting loss can be surrendered for a payable credit at 14.5%, working out at an effective cash benefit of roughly 27% of qualifying R&D expenditure. That's close to double the net benefit available under the standard merged scheme.

A Worked Example

Take a loss-making, early-stage software company spending £200,000 on genuinely qualifying R&D, out of £250,000 total expenditure — comfortably above the 30% intensity threshold. Under ERIS, that £200,000 attracts enhanced relief worth roughly £54,000 in cash back from HMRC — a meaningful lifeline for a company still some way from profitability, and a very different outcome from the standard merged scheme's roughly 15% to 16.2% net benefit.

What R&D Costs Can Be Claimed?

Staff Costs

Salaries, employer National Insurance, and pension contributions for staff directly engaged in the qualifying R&D project are claimable, generally apportioned by the genuine proportion of their time spent on the project itself.

Subcontractors and Externally Provided Workers

Costs for subcontracted R&D work and externally provided workers can qualify, though the rules here are genuinely intricate following the 2024 changes — particularly around who's entitled to claim when the work spans more than one company, as touched on above.

Software, Consumables and Utilities

Software licences used directly in the R&D activity, consumable materials used up during the project, and a proportion of relevant utility costs — power, water, and similar — used specifically in the R&D process can all form part of a claim.

What You Generally Can't Claim

Capital expenditure doesn't qualify for R&D relief in the same way — it's relieved instead through capital allowances, covered in our dedicated guide. Production costs once a product has moved beyond genuine R&D into routine manufacturing, and general overheads not specifically tied to the R&D activity, are similarly excluded.

R&D Claim Notification and Additional Information

The Claim Notification Form

Certain companies now need to notify HMRC in advance that they intend to make an R&D claim, before they actually submit it — this applies particularly to first-time claimants, and to companies that haven't made a claim recently. Miss this notification where it's required, and the claim can be blocked outright, regardless of how strong the underlying technical work actually was.

The Additional Information Form

Every R&D claim now needs a detailed Additional Information Form submitted alongside it, setting out the qualifying projects, the technical uncertainties addressed, and a breakdown of the costs involved — submitted before, or on the same day as, the Company Tax Return that contains the claim itself.

Why Missing Either One Kills the Claim

This is the part I can't overstate: these aren't optional formalities that HMRC quietly overlooks if the rest of the claim is strong. Miss the notification deadline where it applies, or fail to submit the Additional Information Form correctly, and the claim is rejected on procedural grounds alone — no assessment of the underlying R&D even takes place. It's exactly why we build the compliance timeline into an R&D claim from the very start of the conversation, rather than treating the paperwork as an afterthought once the technical narrative is written.

R&D relief remains one of the most valuable reliefs available to an innovating company — but it's no longer a claim you can put together casually in the weeks before your filing deadline. If your business has genuinely pushed through a difficult technical problem this year, even one that didn't feel like "research" at the time, it's worth a proper conversation before you assume it doesn't qualify. Get in touch with the team at Cannon Accountants, and we'll help you work out whether a claim genuinely stacks up, and build it to survive scrutiny from the outset.

For the wider picture of how R&D relief fits alongside corporation tax, capital allowances and everything else covered in this series, head back to our complete Limited Company Tax Guide 2026/27: Corporation Tax, Dividends & Director Tax →.

Disclaimer:

The content of this blog is for general informational purposes only and should not be considered professional tax advice. The information is correct at the time of publishing but may change following future UK budget announcements or updates to HMRC guidance. Individual circumstances vary, and tax obligations can differ based on your personal situation. We strongly recommend consulting with us or a qualified tax professional to receive advice tailored to your specific needs.