The R&D tax credit regime has always been a bit of a black box. You knew the relief existed, you knew it was generous, and for a certain type of growth-stage tech company, it was baked into the cashflow model as near-certain income. Then HMRC tightened the screws. Between 2023 and 2026, the reforms reshaped eligibility, merged two separate schemes, introduced new compliance requirements, and launched an aggressive wave of enquiries that caught a lot of scaleups off guard. The era of loose claims and optimistic interpretations is firmly over.
For finance directors and engineering leads at UK scaleups, the question now is not whether to claim R&D tax credits but how to claim them correctly, sustainably, and in a way that survives scrutiny. That requires understanding what actually changed and why HMRC is looking so hard at this particular corner of the tax system.
What Changed Between 2023 and 2026
The headline reform was the merger of the SME R&D scheme and the Research and Development Expenditure Credit (RDEC) into a single merged scheme, which came into effect for accounting periods beginning on or after 1 April 2024. The merged scheme broadly follows the old RDEC structure, giving a 20% above-the-line credit rate, which is less generous than the SME scheme’s enhanced deductions for most loss-making companies. For many early-stage scaleups that had been loss-making and relying on the SME payable credit, that was a material reduction in cash recovered per pound spent.
Alongside the merger, HMRC introduced mandatory Additional Information Forms (AIFs), which must be submitted before any R&D claim goes in. These forms require companies to describe their qualifying projects in detail, name the projects, identify the field of science or technology involved, and explain the specific uncertainty they were trying to resolve. Vague descriptions of broadly innovative work no longer cut it. HMRC wants evidence that a company has genuinely tried to resolve a technological or scientific uncertainty, not just built something difficult or used cutting-edge tools someone else developed.
Which Sectors Are Under the Most HMRC Scrutiny
HMRC has been public about targeting high-risk sectors and agent populations. Software development has faced the most sustained scrutiny, largely because historic claims in this area were often padded. Companies routinely claimed for routine application development, UI work, or database management that did not meet the legal standard of advancing knowledge or capability in a field of science or technology. HMRC’s own guidance makes clear that developing software using existing techniques, even complex ones, is not qualifying R&D unless the project itself is advancing the field.
The construction tech sector has also attracted attention, as have companies in life sciences, biotech, and advanced manufacturing. Fintech scaleups that built proprietary risk models or novel algorithmic approaches have generally fared better, provided they can articulate the scientific uncertainty clearly, but even here, HMRC has challenged claims where the innovation could be dismissed as applying known machine learning frameworks to new datasets.
Professional services firms that filed large claims on behalf of clients are also under pressure. HMRC has pursued several R&D claim specialists through civil and criminal channels, and some of the resulting attention has landed on the companies whose claims were exaggerated, not just the advisers who prepared them. Ignorance is not a defence.
What Expenditure Actually Qualifies in 2026
The core definition has not changed as dramatically as the compliance environment around it. R&D tax credits UK scaleups HMRC 2026 discussions still centre on the same basic test: was the company seeking an advance in overall knowledge or capability in science or technology, and did it face genuine uncertainty that a competent professional in the field could not easily resolve?
Qualifying costs include staffing costs for employees directly engaged in R&D, externally provided workers (with some restrictions), subcontractor costs at a reduced rate under the merged scheme, software licences used in R&D, consumables, and data and cloud computing costs that were explicitly clarified as eligible from April 2023. That last one matters a lot for SaaS scaleups running heavy inference workloads or training custom models on proprietary data.
What does not qualify: routine testing, bug fixing, replication of existing solutions, project management of R&D rather than R&D itself, and most commercially driven product development that does not involve resolving a specific scientific or technological uncertainty. The line is not always obvious, and that ambiguity is where most disputes arise. According to HMRC’s official guidance on R&D relief, the advance must be something the field of science or technology as a whole did not previously know or could not previously do, not just something novel to your specific business.
How Finance and Engineering Teams Are Restructuring Their Approach
The scaleups that are managing this well have made R&D documentation a live process, not an annual retrospective exercise done by an accountant in a quiet room six months after the work finished. That shift is the most important structural change happening across the sector right now.
Engineering leads are being brought into the tax process much earlier. Some companies have appointed a dedicated R&D lead, sometimes sitting within the finance function, sometimes within product and engineering, whose job is to log qualifying work in real time, using internal tools like Jira tagging systems, sprint retrospectives, or dedicated project diaries that capture what uncertainty existed at the start of a piece of work, what approaches were tried, and what was learnt. This kind of contemporaneous documentation is far more defensible under enquiry than a reconstruction written months later.
Finance teams at R&D tax credits UK scaleups aware of HMRC scrutiny are also being far more selective about what goes into a claim. The instinct to maximise the claim by including borderline projects is being replaced by a more conservative approach, driven by the cost of an enquiry in management time, legal fees, and reputational risk. A smaller, rock-solid claim beats a larger one that triggers a six-month investigation.
Pre-notification, introduced for some claim categories, has also changed the rhythm. Companies need to notify HMRC of their intention to claim within six months of the end of the accounting period, which means the compliance calendar has tightened considerably.
What Scaleups Should Be Doing Right Now
If you have not reviewed your R&D claim methodology since 2022, that is overdue. The specific actions worth prioritising: get your qualifying project descriptions stress-tested against the current HMRC guidance, not the guidance that existed when you first started claiming. Make sure your engineering team understands what uncertainty means in a legal tax context, because it is narrower than the everyday use of the word. And if your previous claims were prepared by a third-party adviser who was charging on a percentage-of-claim basis, review those carefully before they inform your next submission.
The underlying opportunity has not disappeared. R&D tax relief remains one of the most generous mechanisms available to UK technology businesses, and for genuinely innovative scaleups doing hard technical work, the merged scheme still delivers significant value. The clampdown is not anti-innovation; it is anti-abuse. The companies that treat documentation as a core engineering discipline rather than a finance afterthought will continue to benefit. The ones that do not will find that HMRC’s patience for guesswork has run out entirely.
Frequently Asked Questions
What is the merged R&D tax relief scheme and how does it affect UK scaleups?
The merged scheme, effective for accounting periods beginning on or after 1 April 2024, combines the old SME and RDEC schemes into a single structure with a 20% above-the-line credit rate. For loss-making scaleups that previously claimed the generous SME payable credit, this typically means less cash recovered per pound of qualifying spend, making accurate and thorough claims even more important.
Why is HMRC scrutinising R&D tax credit claims so heavily in 2026?
HMRC identified significant levels of non-compliance and outright fraud in the R&D relief system, estimated to cost hundreds of millions of pounds annually. Software development and sectors with high claim volumes attracted particular attention, partly because many companies were claiming for routine development work that did not meet the legal standard of advancing science or technology. The Additional Information Form requirement was introduced specifically to force more rigorous upfront justification.
Can cloud computing and data costs qualify for R&D tax credits?
Yes, since April 2023, expenditure on cloud computing and data costs directly used in qualifying R&D activity has been eligible. For SaaS companies and AI-focused scaleups, this can include costs for compute used in model training or experimentation, provided the underlying work meets the qualifying criteria around scientific or technological uncertainty.
What documentation does HMRC expect for an R&D tax credit claim?
HMRC expects companies to complete an Additional Information Form before submitting a claim, detailing each qualifying project, the field of science or technology involved, the specific uncertainty the company sought to resolve, and the work carried out. Contemporaneous records such as engineering logs, sprint notes, or project diaries that were created during the work, not after, are far more credible under enquiry than retrospective reconstructions.
Does routine software development qualify for R&D tax credits?
Generally, no. HMRC’s guidance is clear that applying existing software techniques, even sophisticated ones, to a new business problem does not constitute qualifying R&D unless the project itself advances the overall capability of science or technology in a way that was not previously known or achievable. Developing a standard e-commerce platform, even a complex one, would not qualify, whereas developing a novel algorithm that genuinely pushes the state of the art in a technical field might.
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