Over the past 12 months, the UK’s R&D tax landscape has continued to evolve, driven by legislative reform, a more targeted HMRC compliance approach and an investment market that remains sensitive to uncertainty.
For PE‑backed businesses and management teams preparing for investment, keeping pace with these developments is critical to maintain investor confidence and support a smooth transaction process. R&D tax is no longer just a compliance exercise. It now affects due diligence and valuation.
HMRC is more targeted, but expectations are higher
HMRC’s enquiry model is more selective and risk‑driven, with the Wealthy and Mid‑Sized Business Compliance (WMBC) team focusing on more complex risks rather than the broad, high‑volume interventions seen in previous years. Campaign ‑ and project‑ led enquiries are also expected to be worked through to resolution.
This shift makes it easier to anticipate where HMRC is likely to challenge, but it also raises expectations around technical robustness, consistency and the quality of supporting evidence.
What has changed in practice
1. HMRC enquiries are less blanket, more targeted
In 2026, HMRC’s attention has moved more firmly towards claims perceived as higher risk. The areas currently challenged include:
- technical eligibility of projects against statutory guidelines
- costing methodologies and whether the financials are robust and supportable
- the quality, credibility and consistency of supporting documentation
Interpretation of the contracted‑out R&D rules, and the application of HMRC guidance, remains an area of uncertainty, with HMRC’s approach in practice not yet fully clear. While we have not seen consistent challenge in this area to date, it is widely expected to become a key focus of scrutiny over the next 12 to 24 months given the limited established precedent. This increases the importance of reviewing carefully and evidencing who the decision-maker is or who is initiating the R&D activity.
For businesses that prepare well, this more targeted approach can reduce unnecessary disruption, but only where claims are fully evidenced and clearly aligned with current legislation and HMRC expectations.
2. R&D tax changes are now flowing through to EBITDA and valuations
With the merged scheme, based on the research and development expenditure credit (RDEC) model, applying to accounting periods beginning on or after 1 April 2024, most companies have now had to engage with the new rules. For some, particularly those with later year ends, the full financial and operational impact is only now being fully assessed.
Businesses are increasingly modelling not only the cash benefit, but also the above-the-line accounting impact, which continues to influence EBITDA, valuations and deal discussions.
The Enhanced R&D Intensive Scheme (ERIS) remains a key relief for qualifying loss‑making SMEs, particularly where R&D underpins core activity and IP creation. Investors are placing greater scrutiny on whether portfolio companies meet the 30% qualifying expenditure threshold, and whether that position is sustainable rather than driven by short‑term or one‑off factors.
3. Transactions and investor expectations: diligence is sharper than ever
R&D tax incentives continue to feature prominently in diligence and negotiations. While the surge in HMRC challenge over recent years led some buyers to discount R&D receivables, the more focused enquiry landscape is starting to reduce, but not eliminate, that uncertainty.
Investors are increasingly asking:
- Are claims defensible under updated legislation and HMRC practice?
- Has the business adapted appropriately to the contracted‑out R&D rules?
- Have advance notification requirements been met?
- Are claim methodologies consistent with both technical narratives and financial data?
- Are historic claims exposed to enquiry or potential clawback?
Poorly evidenced or inconsistent claims represent a potential liability in a transaction context. Advisors can play a key role in providing additional assurance around historic claims and supporting a more robust approach and methodology going forward.
Optimised, well-governed claims are increasingly seen as an asset, either as a robust RDEC increment to EBITDA or as an equity value uplift at completion.
4. The administrative burden remains
Even with fewer blanket enquiries, HMRC now expects stronger evidence across every stage of a claim. This includes:
- clear identification of qualifying projects
- clear articulation of technological uncertainties
- defensible cost attribution methodologies
- clarity over contracted‑out and externally provided worker arrangements
Recent case law, including Beer Express Ltd v HMRC, highlights the risks of weak documentation. The Tribunal’s decision turned on the absence of competent professional involvement, credible technical evidence and supporting records. This reinforces the importance of maintaining robust, contemporaneous documentation.
For PE‑backed management teams, embedding this level of governance is increasingly a core component of investor readiness.
5. Opportunities remain, particularly for businesses that modernise their approach
Despite tighter rules and more forensic oversight, R&D incentives continue to offer meaningful upside through better‑targeted and optimised claims.
Businesses that invest in strong governance, refine claim methodologies and embed year‑round documentation processes are better positioned to:
- reduce enquiry exposure
- accelerate cashflow
- optimise claim outcomes under the new rules
- protect value through transactions
These practices increasingly distinguish businesses that simply meet compliance requirements from those using R&D incentives strategically to support growth.
What PE‑backed businesses should do now
- Invest in digital tools and real‑time data capture: Embed real‑time R&D data capture to strengthen evidence, improve accuracy and enhance diligence readiness.
- Refresh claim methodologies: Ensure alignment with the merged regime and address key risk areas such as contracted‑out R&D and overseas expenditure restrictions.
- Strengthen documentation ahead of submission: Targeted enquiries mean HMRC expects claims to be fully evidenced and readily defendable.
- Reassess valuation and deal impacts: Above‑the‑line credits continue to influence EBITDA and enterprise value discussions.
- Engage early ahead of transactions: Buyers and their advisors are undertaking increasingly detailed reviews of R&D governance and claim quality.
Conclusion
Twelve months on, the UK R&D tax landscape remains complex, but more predictable for those who are well prepared. HMRC’s approach is now less sweeping, but more targeted, detailed and risk driven.
For PE investors and their portfolio companies, adapting to this environment is not optional. It is central to protecting value, ensuring compliance and maintaining deal momentum.
