R&D tax relief is one of the most valuable incentives available to UK innovation businesses — a direct reduction in Corporation Tax liability, or in some cases a cash payment from HMRC, in exchange for carrying out qualifying research and development activity. For qualifying companies, the relief can be worth 15 to 27 pence for every pound of eligible R&D expenditure.
It is also one of the most heavily scrutinised areas of corporate taxation in 2026. HMRC opened over 3,000 R&D compliance checks in 2025/26, a figure that represents a significant acceleration from previous years and reflects the department's assessment that a substantial proportion of claims submitted between 2018 and 2023 were either inaccurate or fraudulent. Many of those checks targeted claims prepared by specialist R&D advisory firms that had minimal understanding of the technical requirements and were focused on generating fee income from large claim percentages rather than building claims that could withstand scrutiny.
The result is that in 2026, the standard for a defensible R&D claim is materially higher than it was even three years ago. The evidence required, the technical narrative demanded, and the documentation that must be in place before a claim is submitted are all significantly more demanding. And the penalty for getting it wrong — a compliance check that reverses the claim and potentially opens prior years — is a serious operational and financial risk for any business.
At CoreAcc Accountants, we help clients across Hertfordshire and North London build R&D claims that are technically robust, well documented, and capable of withstanding the most searching HMRC review. This guide explains the current regime in full, with worked examples and answers to the questions we hear most often.
Disclaimer: This article is for general information only and does not constitute professional tax advice. R&D claims are highly fact specific. Always seek specific advice for your individual circumstances.
1. The Merged Scheme: What Changed from April 2024
The most fundamental change to R&D tax relief in a decade took effect for accounting periods beginning on or after 1 April 2024. HMRC abolished the separate SME R&D Relief scheme and the large company Research and Development Expenditure Credit scheme and replaced them with a single merged RDEC scheme that applies to all companies regardless of size.
For accounting periods beginning before 1 April 2024, the old two track system still applies. But for accounting periods beginning on or after that date — which means the current financial year for most calendar year companies and the year beginning April 2024 for April year end companies — the merged scheme is the only route.
How the merged scheme works
Under the merged RDEC scheme, qualifying companies receive an above the line credit equal to 20% of qualifying R&D expenditure. Above the line means the credit appears as income in the company's profit and loss account, increasing reported profit before Corporation Tax is applied. The credit is then used to offset the company's Corporation Tax liability.
For a profitable company paying Corporation Tax at the main rate of 25%, the net benefit after deducting Corporation Tax on the credit itself is approximately 15% of qualifying R&D spend — meaning the government effectively contributes 15 pence for every pound the company spends on qualifying R&D.
For a profitable company at the small profits rate of 19%, the net benefit is approximately 16.2% of qualifying spend.
Where the credit exceeds the company's Corporation Tax liability, the excess can be carried back to the previous year or forward to future years, or in some cases paid as a cash credit to the company. The payability rules are more restricted under the merged scheme than they were under the old SME scheme, and a profitable company will in most cases use the credit to offset its CT liability rather than receive a cash repayment.
How the merged RDEC compares to the old SME scheme
Under the old SME R&D Relief scheme, qualifying companies received an enhanced deduction of 230% of qualifying expenditure — meaning £230 of deductible cost for every £100 spent. For a profitable company at the old 19% CT rate, the net benefit was approximately 24.7%. For a loss making SME, the old scheme allowed the company to surrender the enhanced loss and receive a cash credit of 14.5% of the surrenderable loss.
The merged scheme is therefore less generous than the old SME scheme for many companies, particularly those that were loss making and relying on the cash credit. This is why the Enhanced R&D Intensive Support scheme — ERIS — was introduced alongside the merged scheme to provide additional support for the most R&D intensive SMEs.
2. ERIS: The Enhanced Scheme for R&D Intensive SMEs
The Enhanced R&D Intensive Support scheme is available to small and medium sized companies where qualifying R&D expenditure represents at least 30% of total expenditure for the accounting period. It provides a more generous effective benefit than the standard merged scheme.
Under ERIS, the qualifying company receives a 35% RDEC credit rather than the standard 20%. The net benefit for a loss making ERIS company that claims the payable credit is approximately 27% of qualifying R&D expenditure — meaningfully higher than the standard merged scheme and more comparable to the old SME scheme for R&D intensive businesses.
A company qualifies as an SME for ERIS purposes if it has fewer than 500 employees and either turnover not exceeding €100 million or a balance sheet total not exceeding €86 million. The 30% R&D intensity threshold is tested by dividing total qualifying R&D expenditure by total expenditure for the period.
ERIS is particularly valuable for technology startups, biotechnology companies, and software businesses in their early stage before significant commercial revenue is generated, where the majority of costs relate to developing a product or process that does not yet generate commercial income. A startup spending £600,000 of which £420,000 relates to qualifying R&D (70% intensity) is well above the 30% threshold and can access the higher ERIS rate.
Worked Example 1: Merged RDEC vs ERIS for a Technology Startup
Luminary AI Ltd is developing a proprietary machine learning platform. In its year ending 31 March 2026, it has total expenditure of £800,000 of which £560,000 relates to qualifying R&D (70% intensity). The company is loss making.
Under the standard merged RDEC scheme: credit at 20% of £560,000 = £112,000. The company can receive this as a payable credit (subject to the PAYE cap — see below). Net benefit: £112,000.
Under ERIS (which applies because R&D intensity exceeds 30%): credit at 35% of £560,000 = £196,000. Net benefit: £196,000 — an additional £84,000 compared to the standard merged scheme.
ERIS must be claimed actively — it does not apply automatically. The company must elect to apply ERIS on its Corporation Tax return and demonstrate in its Additional Information Form that the 30% intensity threshold is met.
3. What Qualifies as R&D: The Technological Uncertainty Test
This is where the majority of compliance failures arise. HMRC's definition of qualifying R&D is specific and demanding, and it bears little resemblance to the colloquial use of the term.
R&D for tax purposes is defined by the Department for Science, Innovation and Technology guidelines as activity that seeks to achieve an advance in overall knowledge or capability in a field of science or technology by resolving a scientific or technological uncertainty. The advance must be in overall knowledge — not just in the knowledge of the company making the claim — and the uncertainty must be one that a competent professional in the relevant field could not readily resolve by reference to existing knowledge.
Each element of this definition matters.
The advance must be in science or technology, not in commerce, social science, or the arts. Developing a better customer service process is not R&D. Developing a new algorithm that processes data in a way not previously demonstrated in the field of computer science may well be.
The advance must be in overall knowledge. If the answer to your technical problem can be found in an academic paper, a standard textbook, or by consulting another expert in the field, there is no advance in overall knowledge — there is simply the company's own catch up with existing knowledge. Many claims fail on this point: the company genuinely did not know how to solve the problem, but the solution was already known to competent professionals in the field.
The uncertainty must be genuine. The test is whether a competent professional — someone with appropriate skills and knowledge in the relevant scientific or technical discipline — could have resolved the uncertainty by applying their existing knowledge without conducting research or development. If a senior engineer could have designed the solution using established engineering principles without experimentation or investigation, the work does not qualify.
What typically qualifies
Activities that typically meet the definition include the development of novel algorithms where no existing computational approach achieves the required outcome, the creation of new software architectures that process or manage data in a way not previously demonstrated, the engineering of new materials or formulations with properties not achievable through existing techniques, the resolution of integration challenges between systems where no documented solution exists, the development of new manufacturing processes that achieve outcomes not possible with current techniques, and basic or applied scientific research directed at establishing new knowledge.
What typically does not qualify
Activities that typically do not meet the definition include the application of existing software frameworks or libraries to build standard commercial applications, the configuration or implementation of commercial off the shelf software packages, the development of websites, mobile applications, or e commerce platforms using established tools and techniques, the resolution of bugs or performance issues in existing software using standard debugging approaches, and market research, feasibility studies, or business analysis — even where these inform a technical project.
The boundary is not always obvious. A software development project may include both qualifying and activities that do not qualify within the same year. The qualifying activities are those that involve genuine technical uncertainty; the activities that do not qualify are those that apply existing techniques to build out a known solution. Only the qualifying activities — and the associated qualifying expenditure — form part of the claim.
4. What Expenditure Qualifies
Identifying qualifying R&D activity is only half the work. Once the qualifying activities are established, each category of expenditure relating to those activities must be mapped to the qualifying expenditure categories recognised by the merged scheme.
Staff costs
Staff costs are the most significant qualifying cost category for most businesses. Qualifying staff costs include the salaries, wages, bonuses, employer National Insurance contributions, and employer pension contributions for employees directly and actively engaged in qualifying R&D activities.
Where an employee spends only part of their time on qualifying R&D — which is the case for most technical staff who also undertake project management, client liaison, or general administration — only the portion of their cost attributable to qualifying R&D activities is included. This apportionment must be evidenced by time records, project logs, or a documented methodology for allocating staff time between qualifying and work that falls outside the qualifying definition.
Indirect supporting activities — administration, IT support for the R&D team, maintenance of equipment used in R&D — are qualifying indirect activities and can be included at a proportionate cost, but HMRC scrutinises indirect cost claims carefully. General overhead costs such as rent, utilities, and management time are not qualifying expenditure under the merged scheme.
Externally Provided Workers
Where technical staff are provided through an agency or staffing company — a common arrangement in the software and technology sector — the cost of those workers is qualifying expenditure at 65% of the payment made to the staff provider. This 65% cap reflects the fact that the staff provider receives a margin on top of the worker's salary, and only the worker's underlying cost is genuinely attributable to the R&D activity.
For companies that use significant numbers of contract developers or technical specialists through agencies, the 65% EPW restriction can have a material impact on the size of the qualifying cost pool.
Subcontractors
Where the company subcontracts some or all of its R&D activities to another party — a specialist laboratory, a software development company, or an individual consultant — the treatment depends on whether the subcontractor is connected to the claimant company.
For unconnected subcontractors dealing at arm's length, 65% of the payment made to the subcontractor is qualifying expenditure. For connected subcontractors — companies under common ownership or control — the qualifying expenditure is the lower of 65% of the payment made and the actual cost incurred by the subcontractor in performing the R&D. This prevents inflated transfer pricing between connected parties from increasing the size of the R&D claim.
Crucially, subcontractor expenditure only qualifies where the company commissioning the work is the party bearing the financial risk of the R&D and retaining the rights in its outcome. If the subcontractor is conducting its own R&D and simply licensing the results to the claimant, the claimant is not entitled to claim the cost as qualifying R&D expenditure — the subcontractor may be entitled to make its own claim instead.
Consumables and software
Consumables — materials, substances, or other items used or consumed directly in the R&D process — are qualifying expenditure. Software licences used directly in the R&D activity are also qualifying expenditure. The key condition in both cases is "directly" — the consumable or software must be used in the qualifying R&D activity itself, not in the general business operations of the company.
Overseas expenditure
With effect for accounting periods beginning on or after 1 April 2024, the qualifying expenditure categories have been restricted to restrict overseas R&D expenditure. Work performed outside the UK by staff employed overseas, or subcontracted to overseas parties, is generally excluded from qualifying expenditure under the merged scheme.
The restriction is not absolute. Where it was not possible for the claimant to have the activity undertaken in the UK — for example because specific geographical, environmental, or regulatory conditions required the activity to take place in a particular overseas location — the overseas expenditure may still qualify. Cost saving is explicitly not a valid justification for overseas R&D expenditure remaining in the qualifying pool.
For companies that previously relied heavily on overseas development resource — offshore software development centres, overseas laboratory facilities, or international subcontractors engaged primarily for cost efficiency — this restriction may materially reduce the size of the qualifying expenditure pool.
5. The Additional Information Form: What HMRC Requires
The mandatory Additional Information Form was introduced in August 2023 and applies to all R&D claims for accounting periods beginning on or after 1 April 2023. It must be submitted digitally through HMRC's online portal before the Corporation Tax return is filed. An R&D claim included in a CT600 without a prior AIF submission is automatically invalid — HMRC's systems will reject the claim without review.
The AIF has several sections, each of which requires substantive content rather than generic description.
The technical narrative
The most important section of the AIF is the technical narrative — the description of each R&D project, what technological uncertainty it sought to resolve, how the company went about resolving it, and what the outcome was. HMRC reviewers use the technical narrative to assess whether the claimed activities meet the definition of qualifying R&D.
A poor technical narrative is the most common reason HMRC opens a compliance check on an R&D claim. Narratives that describe what the company built rather than why it was technically uncertain — that explain the commercial outcome without addressing the scientific or technological challenge — are routinely challenged. The narrative must be written with the technological uncertainty test explicitly in mind, describing what was not known at the outset, why it could not be resolved without R&D, what approaches were explored, and what uncertainty remained at the end of the period if the project was incomplete.
Cost breakdown
The AIF requires a breakdown of qualifying expenditure by category — staff costs, EPWs, subcontractors, consumables, software, and any other qualifying items. Each category must be supported by underlying calculation, and the apportionment methodology for costs that relate only partially to qualifying activities must be explained.
HMRC expects the cost breakdown to be mathematically reconcilable to the company's accounts. Where the costs claimed do not obviously match the accounts — because of apportionment, because certain staff costs have been excluded, or because indirect costs are included at a proportionate rate — the methodology should be documented.
Senior officer sign off
A named senior officer of the company — typically a director — must personally certify the accuracy of the AIF. This certification is not a formality. The director is personally confirming that they have reviewed the content of the form and that it accurately represents the qualifying activities and costs of the company. Where a claim is found to be inaccurate or fraudulent, this certification is relevant to the question of whether penalties should be applied personally as well as to the company.
6. Pre Notification: The Deadline Most Companies Miss
From 1 April 2023, companies that are making an R&D claim for the first time, or that have not claimed in the previous three years, must submit a pre notification to HMRC within six months of the end of the accounting period to which the claim relates.
Pre notification is a brief online form that alerts HMRC to the company's intention to make a claim. It does not require the claim to be fully prepared at this stage — it simply reserves the right to make the claim by the required deadline.
Missing the pre notification deadline permanently bars the claim for that accounting period. There is no extension and no appeal process on this point. A company whose year ended 31 March 2026 and that is making its first R&D claim must submit the pre notification by 30 September 2026. If it misses that deadline, no claim can be made for the year ending 31 March 2026, regardless of how compelling the qualifying activity may be.
For companies that are regular claimants — those that have claimed in each of the previous three years — pre notification is not required. But any lapse in annual claiming, even of a single year, resets the pre notification requirement.
7. What Triggers an HMRC Compliance Check
HMRC uses a combination of risk based criteria and random selection to determine which R&D claims to examine. Understanding what the higher risk indicators are can help companies and their advisers calibrate the quality of evidence needed.
Claims prepared by R&D advisory firms that have appeared in previous HMRC enquiries or that are associated with high volumes of claims from particular industry sectors attract elevated scrutiny. HMRC maintains intelligence on the R&D advisory market and targets firms that it believes have been generating inflated or inaccurate claims.
Claims where the size of the credit is disproportionate to the scale of the company attract attention. A micro company with two employees claiming £400,000 of qualifying staff expenditure is statistically unlikely to have that level of genuinely qualifying activity.
Claims where the qualifying expenditure is entirely or predominantly subcontractor expenditure — particularly where the subcontractor is a connected party — are a focus area. The connected party rules and the 65% cap on subcontractor costs are specifically designed to prevent inflated claims through related party structures.
Claims where the technical narrative is generic, does not describe specific technological uncertainties, or could have been written about any company in the sector rather than being specific to the claimant's actual activities are flagged for review.
First time claimants and claimants returning after a gap are subject to enhanced review, which is part of the rationale for the pre notification requirement.
Worked Example 2: A Claim That Triggered a Compliance Check
Horizon Digital Ltd is a software development agency. In its year ending 31 December 2024, it submitted an R&D claim prepared by a specialist R&D adviser claiming £180,000 of qualifying expenditure, generating a credit of £36,000 under the merged scheme.
The claim described the company's work as "developing novel software solutions using innovative approaches to data management and user experience design." No specific technological uncertainty was identified. The cost breakdown included 80% staff costs allocated across the entire development team without any apportionment methodology. The AIF was filed but contained minimal technical narrative.
HMRC opened a compliance check eight months after the claim was filed. In the course of the check, it became apparent that the company's work primarily involved building standard e commerce and business management applications using established frameworks such as React, Node.js, and standard cloud architecture patterns. The development team were applying existing techniques to client projects, not resolving genuine technological uncertainty. HMRC rejected the claim in full and charged interest on the credit that had been offset against the company's Corporation Tax liability.
Horizon's experience was not unusual. The claim failed because it described what the company did rather than why it was technically uncertain. A defensible claim would have identified the specific projects where genuine uncertainty existed — if any — and would have excluded the routine application development work that formed the bulk of the team's activity.
Worked Example 3: A Defensible Claim for a SaaS Business
Pathfinder Analytics Ltd develops a B2B data analytics platform. In its year ending 31 March 2026, it employs six engineers of whom three spend approximately 70% of their time on qualifying R&D.
The R&D activity centres on two projects. The first involves developing a proprietary algorithm for real time anomaly detection in large, sparse datasets — an area where the existing literature provides no solution that performs adequately at the scale required. The second involves building a novel data compression architecture that reduces storage requirements by a factor that has not previously been demonstrated with this class of data. Both projects involve genuine technological uncertainty — the engineers have explored multiple approaches, not all of which have succeeded, and the work is genuinely investigative rather than the application of known techniques.
The qualifying expenditure calculation: three engineers at an average loaded cost of £72,000 each (salary plus employer NI and pension) multiplied by 70% qualifying time = £151,200. Software licences used directly in the development work: £8,400. Qualifying cloud computing costs (specifically attributable to R&D activity): £6,200. Total qualifying expenditure: £165,800.
RDEC credit at 20%: £33,160. Net benefit after Corporation Tax at 25%: approximately £24,870.
The AIF for this claim contains detailed technical narratives for each project, describing the specific uncertainty at the outset, the approaches explored, and the extent to which uncertainty remains. Staff costs are supported by time records showing each engineer's allocation between qualifying R&D and project delivery work that falls outside the qualifying definition. The claim is supported by a senior director sign off and prepared by CoreAcc Accountants with input from the company's technical leads. This claim is defensible.
8. Advance Assurance: Reducing Risk Before You Claim
HMRC offers an Advance Assurance scheme specifically for R&D claims. Companies that have not previously claimed and are making their first claim can apply for Advance Assurance before filing, receiving a formal written confirmation from HMRC that the proposed claim meets the qualifying conditions based on the information provided.
Advance Assurance does not guarantee immunity from a compliance check, but it provides a strong evidential basis for the claim and significantly reduces the risk of a rejection. Where HMRC has confirmed in advance that the company's activities and costs meet the qualifying criteria, it is much harder for a subsequent compliance check to reverse the claim without identifying new information that was not disclosed in the Advance Assurance application.
The Advance Assurance process typically takes four to eight weeks. For a company making a first claim with significant expenditure, the time invested in an Advance Assurance application is well spent — it forces early and rigorous engagement with the definition of qualifying R&D and produces documentation that can underpin both the first claim and subsequent annual claims.
9. The Success Fee Model: Why It Is Now a Risk Factor
For many years, the dominant business model for R&D advisory firms was the success fee — a contingent fee calculated as a percentage of the R&D credit obtained, often ranging from 15% to 40% of the credit value. This model created a misalignment of incentives: the adviser was motivated to maximise the size of the claim rather than to ensure its accuracy, and the business owner had little visibility of how the claim was constructed.
HMRC identified this dynamic as a significant contributor to the inflation of R&D claims. A company paying a 25% success fee on a £50,000 credit has effectively paid £12,500 for advice that, if the claim is subsequently rejected, leaves it with a £50,000 Corporation Tax liability plus interest and potentially penalties.
The compliance risk associated with contingent fee claims is now a specific risk factor that HMRC uses to prioritise claims for review. Companies that received claims prepared on a success fee basis by advisory firms that have since been dissolved or restructured — a common pattern following HMRC's enforcement activity in 2024 and 2025 — are particularly exposed.
CoreAcc Accountants does not operate on a success fee model. We charge for R&D advisory work on a fixed fee basis agreed in advance. The fee reflects the work required to build a defensible claim, not a percentage of the outcome. This means our incentives are aligned with yours: our goal is a claim that is accurate, well documented, and capable of withstanding scrutiny — not a claim that is as large as possible regardless of its defensibility.
Frequently Asked Questions
What is the merged RDEC scheme and who does it apply to?
The merged RDEC scheme replaced the separate SME R&D Relief and large company RDEC schemes with a single credit of 20% of qualifying R&D expenditure, applying to all companies regardless of size for accounting periods beginning on or after 1 April 2024. The credit appears above the line in the profit and loss account and is used to offset Corporation Tax. For profitable companies paying CT at 25%, the net benefit is approximately 15% of qualifying spend.
What is ERIS and how do I know if I qualify?
ERIS is the Enhanced R&D Intensive Support scheme, available to SMEs where qualifying R&D expenditure is at least 30% of total expenditure for the period. Under ERIS, the credit rate is 35% rather than 20%, giving a higher effective benefit for eligible companies. An SME is a company with fewer than 500 employees and either turnover below €100 million or a balance sheet below €86 million. If your R&D spending represents more than 30% of your total costs, you should model both the standard merged scheme and ERIS to determine which produces the better outcome.
What is the Additional Information Form and when must it be submitted?
The Additional Information Form is a mandatory digital submission that must be made before the Corporation Tax return containing the R&D claim is filed. It contains a technical narrative describing each qualifying project and the technological uncertainty it addressed, a breakdown of qualifying expenditure by category, and a senior officer certification. Submitting the CT600 before the AIF is automatically fatal to the claim — HMRC's systems will not process it. The AIF is submitted through HMRC's online portal using the company's Government Gateway credentials.
What is the pre notification requirement?
Companies making an R&D claim for the first time, or that have not claimed in the previous three accounting periods, must submit a pre notification to HMRC within six months of the end of the accounting period to which the claim relates. Pre notification is a brief online process that reserves the right to claim. Missing the six month deadline permanently bars the claim for that period. For a company with a 31 March 2026 year end making its first claim, the pre notification deadline is 30 September 2026.
What does "technological uncertainty" mean in practice?
A technological uncertainty is one that a competent professional in the relevant scientific or technical field could not resolve by applying existing knowledge without conducting research or investigation. The competent professional standard is important: the uncertainty must be genuine in the field, not just in the company. If the answer to your technical problem can be found in existing literature, by consulting a senior expert, or by applying standard techniques, it is not a technological uncertainty for R&D purposes. The uncertainty must relate to science or technology, not to commercial, organisational, or management matters.
Is overseas R&D expenditure still qualifying under the merged scheme?
Generally no. For accounting periods beginning on or after 1 April 2024, work performed outside the UK is excluded from qualifying expenditure unless it was not possible to perform the activity in the UK due to specific geographical, environmental, or regulatory conditions. Cost saving is not a valid justification. Companies that used overseas development teams, offshore subcontractors, or foreign laboratories primarily for cost efficiency can no longer include those costs in their qualifying expenditure pool. This represents a significant change from the previous regime and has reduced the size of many technology company claims materially.
What is the 65% cap on subcontractor and EPW costs?
Under the merged scheme, payments to subcontractors and Externally Provided Workers qualify at 65% rather than 100% of the amount paid. For subcontractors, this reflects the fact that the payment includes the subcontractor's margin and overheads, not just the underlying R&D cost. For EPWs, it reflects the staffing agency's margin. The 65% cap applies to arm's length arrangements. For connected party subcontractors, the qualifying cost is the lower of 65% of the payment and the actual cost incurred by the subcontractor.
What are the most common reasons HMRC rejects an R&D claim?
The most common reasons for rejection are a failure to demonstrate genuine technological uncertainty — the technical narrative describes what was built rather than why it was technically uncertain; inclusion of activities that apply existing techniques without resolving genuine uncertainty; staff cost apportionment that is not evidenced by time records or a documented methodology; inclusion of overseas expenditure that does not meet the wholly unreasonable test; failure to submit the AIF before the CT600; and missing the pre notification deadline for first time or returning claimants.
How do I know if my R&D adviser is reputable?
A reputable R&D adviser will explain the definition of qualifying R&D clearly and tell you honestly if your activity does not meet it. They will prepare a detailed technical narrative specific to your company's actual work rather than generic descriptions. They will charge a fixed fee rather than a contingent success fee. They will submit the AIF before the CT600 as required. They will be prepared to stand behind the claim in the event of a compliance check and manage any HMRC correspondence on your behalf. If an adviser promises to maximise your claim without asking detailed questions about your technical work, treats the claim as a paperwork exercise, or charges solely on the basis of what they can get from HMRC, treat this as a warning sign.
Can I make a claim myself without a specialist adviser?
Technically yes. The HMRC online portal allows companies to submit their own AIF and include an R&D credit in their CT600 without professional assistance. However, the quality of the technical narrative and cost breakdown is the primary determinant of whether a claim survives scrutiny, and companies without experience in applying the definition of qualifying R&D consistently underestimate the standard required. A claim that is inaccurate — even if the inaccuracy arose from genuine misunderstanding rather than fraud — carries penalties and creates the risk of HMRC examining prior year claims. Professional preparation by an adviser with genuine R&D expertise is an investment, not a cost.
What CoreAcc Accountants Can Help You With
At CoreAcc Accountants, we approach R&D tax relief as a technical discipline that requires both tax expertise and a genuine understanding of what your engineers, developers, and scientists are actually doing. We do not treat every technology project as qualifying R&D. We ask the right questions, apply the technological uncertainty test rigorously, and build claims on the basis of what genuinely qualifies — not on the basis of what would produce the largest credit.
We can help you with claim pre screening — an honest assessment of whether your activities meet the definition of qualifying R&D before significant time is invested in building a claim. We prepare the technical narrative for the Additional Information Form with input from your technical team, ensuring it addresses the specific uncertainties in each project rather than describing the commercial outcome. We calculate qualifying expenditure across all cost categories with a clear and documented apportionment methodology. We submit the pre notification and the AIF before your CT600 deadline. And if HMRC opens a compliance check on your claim, we handle the correspondence and represent you through the process.
Get in Touch
If you believe your company may have qualifying R&D activity, or if you have previously made claims that you are uncertain about in light of the increased HMRC scrutiny, contact CoreAcc Accountants today for a confidential pre screening conversation.
CoreAcc Accountants is an ACCA accredited firm of Chartered Certified Accountants based in Borehamwood, Hertfordshire. This article was published on 10 March 2026 and reflects legislation and HMRC guidance in force at that date, including the merged RDEC scheme applying to accounting periods beginning on or after 1 April 2024. It does not constitute professional tax advice. Always seek specific advice for your individual circumstances.
