Accountant Failed to Claim R&D Tax Credits: Can I Recover the Lost Relief?

Key Takeaways

1. If your accountant failed to make an R&D claim, you may still be able to claim the relief or recover your loss through a professional negligence claim.
2. Qualifying projects seek an advance in science or technology, face technological uncertainty and use systematic investigation rather than routine development.
3. Claims for periods before April 2024 generally had a two-year limit, while some later periods allow three years.
4. If the relief is time-barred, your business may seek the permanent lost benefit, related costs, and any HMRC penalties or interest the accountant caused.
5. Preserve engagement terms, correspondence, tax returns and technical project records, then ask a replacement adviser whether the work qualified.
6. An accountant may breach their duty by overlooking obvious R&D, giving superficial advice, missing deadlines or submitting an inadequate technical narrative.
7. Professional negligence claims generally have a six-year limitation period from breach, so take legal advice before your position worsens.
8. Go Legal is rated Excellent with over 300 five-star reviews and 5/5 on Trustpilot and Google, placing our solicitors among the best-reviewed litigation lawyers in England and Wales.

Can I Recover Relief After an Accountant Failed an R&D Claim?

Often, yes. If your company carried out qualifying R&D and your accountant failed to claim it, you may be able to submit the claim now. If you cannot, you may be able to recover the lost benefit from the accountant.

The sums involved are significant. Typical SME claims range from £25,000 to £250,000 or more, depending on payroll, subcontractor and consumables spend. HMRC’s provisional estimate for 2024/25 was £8.2 billion of R&D tax-relief support on £51 billion of R&D expenditure, across an estimated 40,325 claims, a 17% decrease.

A missed claim usually creates three separate problems:

• The lost tax relief itself.
• The risk of an HMRC enquiry or penalties if a late or corrected claim is made inaccurately.
• A potential professional negligence claim against the accountant.

Our London-based professional negligence solicitors help businesses across England and Wales preserve the relevant records, assess causation and quantify loss. If you need urgent advice, call 0207 459 4037.

Can I Still Claim R&D Tax Relief if My Accountant Missed It?

You may still be able to claim R&D tax relief your accountant missed. It depends on the accounting period, the scheme that applied, whether the company can still amend its corporation tax position and whether any claim-notification requirement was met.

Claims for accounting periods before April 2024 generally had a two-year time limit from the end of the accounting period. For some accounting periods from April 2024, that limit was extended to three years. Establish the deadline for each period separately. Do not assume the relief is permanently lost, and do not assume every period has the same deadline.

Use this decision process:

1. Identify the accounting period and the relief scheme that applied to it.
2. Check whether the two-year or three-year limit applies and whether the corporation tax return can still be amended.
3. Check whether a claim-notification requirement applied, and whether an exception is available.
4. Obtain a replacement adviser’s assessment of technical eligibility and claim value.
5. If relief remains available, submit a compliant claim promptly.
6. If it does not, assess the loss caused by the accountant’s conduct.

Claim Notification Can Bar an Otherwise Valid Claim

The notification requirement applies to accounting periods beginning on or after 1 April 2023. Under HMRC’s claim-notification guidance, a company generally needs to notify HMRC if:

• It is claiming for the first time.
• Its last claim was made more than three years before the last date of the claim-notification period.

HMRC lists exceptions. The notification period starts on the first day of the period of account and ends six months after that period ends. Section 1142A of the Corporation Tax Act 2009 defines the period. HMRC’s manual at CIRD183000 explains that claims under the merged RDEC and ERIS schemes cannot be made after that period unless a specified exception applies.

Missing the notification window can therefore prevent a claim even where the work clearly qualified. The Relief for Research and Development (Content of Claim Notifications, Additional Information Requirements and Miscellaneous Amendments) Regulations 2023 require the notification to include the accounting-period dates, the period-of-account dates, the number of R&D projects and an overview of the projects.

If relief remains available, obtaining it reduces what may be claimed from the accountant. If it is no longer available, the lost benefit may form part of a claim against the accountant. To learn more about this type of dispute, read our article on professional negligence claims.

What Evidence Shows That Your Business Carried Out Qualifying R&D?

Your business carried out qualifying R&D if it sought an advance in science or technology by resolving scientific or technological uncertainty. Good evidence shows that uncertainty and the work done to overcome it.

HMRC’s test, set out at CIRD81300, focuses on the technical work, not the commercial value of the product. The core indicators are:

• The project sought an advance in science or technology.
• The advance was in the wider field, not merely new to the company.
• The team faced scientific or technological uncertainty.
• A competent professional could not readily work out the solution.
• The business used systematic investigation, testing, analysis or prototyping to resolve it.

HMRC explains at CIRD81100 that the advance must improve overall knowledge or capability in the field. Claiming because a product is new to your business, rather than new to the field, is one of the most common reasons claims fail HMRC scrutiny. Under CIRD81910, uncertainty exists where a competent professional cannot readily establish whether something is feasible or how to achieve it.

Why Accountants Miss Qualifying R&D

Accountants often miss R&D because directors describe it as “product development”, “a software upgrade” or “improving our process”, without flagging the technical uncertainty behind it. Some accountants are not trained to spot R&D in a client’s narrative and assume it means laboratories and test tubes. In practice, qualifying work arises in:

• Software, including algorithm development, performance optimisation and integration challenges.
• Engineering, including novel materials, processes and designs.
• Manufacturing, including automation, efficiency and quality control.
• Pharmaceuticals and biotechnology.
• Food and beverage formulation.

HMRC’s guidance on the expectations of claimants says a claimant should identify the project and qualifying field, the specific uncertainties, why a competent professional could not readily resolve them, the existing state of knowledge and why resolving them would be an advance. Many claims fail because the narrative describes product features rather than technical challenges, or does not document the baseline technology and uncertainties.

Useful evidence includes project plans, technical specifications, design iterations, source-code histories, test results, failure logs, board papers, payroll records and invoices for technical work.

The accounts do not settle the question. HMRC’s manual at CIRD80530 confirms that the absence of an R&D disclosure in the accounts does not necessarily mean no R&D took place. Equally, an accountant classifying work as R&D in the accounts does not by itself establish entitlement to relief.

How Do the Merged RDEC and ERIS Rules Affect a Missed R&D Claim?

The scheme that applied to the accounting period fixes the value of the relief the company lost. A loss calculation using the wrong scheme will be challenged by the accountant’s insurer.

The merged RDEC is a taxable credit, so for a company paying corporation tax at 19% the net benefit is 16.2%. For ERIS, a company is R&D-intensive where its qualifying R&D expenditure, including connected-company expenditure, is at least 30% of its total relevant expenditure. HMRC explains this in its guidance on how to identify qualifying R&D activities and at CIRD126000.

Before the merger, the old SME scheme could provide a 130% enhanced deduction (230% total relief) or, in some cases, a payable credit of 14.5%. The old RDEC scheme applied to other companies. Rates changed over time, so each period must be modelled on the rules that actually applied to it.

This creates a transition trap. Many accountants still reference the old SME scheme. An adviser working on periods from 2024 onwards must identify which scheme applies. Failing to recognise the merged scheme may be a breach if it led to no claim or the wrong claim.

For loss purposes, a failure relating to an old SME scheme period is valued under that scheme. A failure relating to a period from April 2024 is valued under merged RDEC or ERIS, which gives many companies lower relief. An inflated figure weakens the claim.

HMRC launched a targeted R&D advance-assurance pilot on 18 May 2026, alongside full-claim advance-assurance guidance for eligible businesses and agents. It is worth raising with your new adviser for future periods.

When Can an Accountant’s Failure to Identify Qualifying R&D Amount to Negligence?

An accountant’s failure may amount to negligence where their work fell below the standard expected for the role they agreed to perform, and that failure caused the company loss.

What Should a Competent Accountant Have Done?

The answer depends on the engagement letter, terms of business, services retained and information available. If the accountant was instructed to prepare corporation tax returns and advise on tax planning, their role may include identifying available reliefs from information the client gave, or would have given on reasonable enquiry.

A competent accountant does not wait for the client to use the term “R&D”. They ask about technical development, software projects, process improvements, prototype testing and unresolved production problems. Where R&D may be relevant, they would:

• Assess whether the work met the test of advance, uncertainty and systematic investigation.
• Prepare or oversee the technical narrative.
• Calculate qualifying costs, such as payroll, subcontractors, consumables and software, within the permitted categories.
• Check claim deadlines and notification requirements.
• Warn the client about HMRC enquiry risk, record-keeping and the consequences of an inaccurate claim.
• Monitor HMRC correspondence, respond to enquiries and advise on amendments.

What Are the Most Common R&D Tax Credit Negligence Errors?

• Never raising R&D relief despite clear qualifying work. This is the most common failure: the accountant simply did not spot it.
• Advising “you don’t qualify” on a superficial assessment, for example “you’re not a pharmaceutical company”.
• Missing the two-year or three-year claim deadline, or a notification requirement.
• Submitting an inadequate technical narrative or failing to retain records, leading to HMRC rejection.
• Including ineligible costs, such as non-qualifying staff, or overstating subcontractor costs.
• Applying the wrong scheme or rates during the transition to merged RDEC and ERIS.
• Ignoring HMRC enquiry letters, or advising withdrawal of a claim without explaining the loss of relief and the prospects of defending it.

HMRC estimated error and fraud in R&D tax relief for 2023/24 at £493 million, or 6.4% of total relief. The SME error rate was 11.1%, representing £347 million. Some of that error stems from poor agent advice.

How Do I Recover Lost R&D Tax Relief From an Accountant?

You recover lost relief through a professional negligence claim. It compares the company’s actual financial position with the position it would probably have been in if the accountant had acted competently.

What Loss Can a Business Claim After an Accountant Missed R&D Tax Credits?

Potential losses include:

• R&D relief or a payable credit that can no longer be obtained.
• Corporation tax that the relief would have reduced or eliminated.
• Repayment of an overclaimed credit, where the accountant submitted an inflated claim that HMRC clawed back.
• HMRC interest and penalties caused by the accountant’s breach.
• Reasonable costs of responding to an HMRC enquiry triggered by a defective claim.
• Fees for a replacement adviser to correct the claim or prepare a late one.
• Finance costs or consequential losses, such as cash-flow damage or a lost investment opportunity, subject to causation, remoteness and the engagement terms, which may exclude consequential loss.

If the claim is time-barred, the company may seek the full value of the relief it would probably have received under the scheme for that period. If the claim remains available, the company must first try to obtain it. The negligence claim then concerns delay costs, finance costs, adviser fees and any reduction in relief caused by scheme changes.

The calculation must also reflect any contribution by the company, such as incomplete records or late information, and whether it took reasonable steps once the breach came to light.

How Do You Prove Causation and Mitigation?

The test is whether, but for the accountant’s breach, the company would have claimed the relief and received it. Where the R&D clearly qualified and the claim would have succeeded, this is usually straightforward.

The accountant may argue that:

• The project did not qualify.
• The company would not have supplied the necessary records even if asked.
• HMRC would have rejected the claim anyway.
• The company caused its own loss by not mentioning the R&D activity.

Your case is strengthened by a replacement adviser’s report confirming the work qualified, records made during the project showing uncertainty and systematic investigation, and evidence the accountant never asked about R&D despite obvious indicators in the management accounts or business plan. Where HMRC would probably have accepted only part of the claim, the loss is the difference between what the company would have received and what it actually received.

What Laws and Deadlines Apply to R&D Tax Relief and Accountant Negligence Claims?

The tax claim deadline and the negligence limitation period are separate. A company can be out of time with HMRC but still in time against the accountant.

Professional negligence claims are generally subject to a six-year limitation period from the breach. Section 14A of the Limitation Act 1980 can provide, in the cases it covers:

• Six years from the date the cause of action accrued.
• Three years from the statutory date of knowledge, if that period ends later.

The Limitation Act 1980 also contains a 15-year longstop for the negligence actions it covers. Which period applies depends on the cause of action, when the loss accrued, when the company obtained the relevant knowledge and the statutory provisions that fit the facts.

How Should I Preserve Evidence and Protect My Position Before Making a Claim?

Preserve the tax evidence and every communication with the accountant before deciding whether to claim. Records are easiest to lose when advisers and staff change.

How to Respond When an Accountant Failed to Claim R&D Tax Credits

1. Secure the engagement letter, terms of business and scope-of-work documents.
2. Download emails, meeting notes, tax returns, computations and HMRC correspondence.
3. Preserve technical records, payroll data and subcontractor invoices before systems, employees or contractors change.
4. Ask a replacement R&D adviser whether a compliant claim remains possible and to quantify what you should have received.
5. If a claim is still possible, submit it to mitigate your loss.
6. Avoid admissions before taking advice if an overclaimed submission is also in issue.
7. Write to the accountant setting out the breach and loss when appropriate. This may prompt them to notify their professional indemnity insurer.
8. Take legal advice on limitation, pre-action correspondence and settlement strategy.

Many professional negligence claims settle before proceedings or at mediation once the accountant’s insurer sees the evidence and a quantified loss. Litigation remains the fallback if settlement fails. Our solicitors can assess breach, causation and the value of your claim before you commit to either route.

Frequently Asked Questions

Speak to an R&D Tax Credit Negligence Solicitor Today

If your accountant failed to identify or claim qualifying R&D, the relief is not lost in every case. Where HMRC can still grant it, a prompt and compliant claim protects your position. Where it cannot, the lost benefit may support a professional negligence claim, provided the accountant’s breach caused the loss.

Delay works against you on both fronts. Tax deadlines and limitation periods run separately, and evidence becomes harder to gather as staff and advisers move on. Our solicitors advise businesses across England and Wales on breach, causation, mitigation and the value of accountant negligence claims.