Navigating the Maze of HMRC Enquires and R&D Tax Credit Claim Enquiries

Reflecting on my decades at HMRC, I understand that dealing with an HMRC enquiry is not straightforward, especially for newcomers. Enquiry work can seem complex. Many may claim they can handle HMRC easily, but managing an HMRC Tax Enquiry is far from simple. It often feels like a dark art.

In reality, navigating the HMRC Tax Enquiry process (or a compliance check) is challenging, even for HMRC Enquiry Officers/Caseworkers.

HMRC enquiries: why process, evidence and judgement matter

Receiving an HMRC enquiry letter can be unsettling.

For many business owners, directors and advisers, the first reaction is not technical. It is practical.

"What has gone wrong?"

That reaction is understandable. An HMRC enquiry can feel unfamiliar, procedural and difficult to read. The opening letter may ask for records, explanations, documents or clarification. It may refer to a particular tax return, claim, period or transaction.

From my experience, most cases take an average of 8 to 12 months to conclude, assuming the issues are straightforward.

An HMRC enquiry is rarely just about the tax calculation. It is also about process, evidence, communication and judgement.

The common misunderstanding

Many people assume that an HMRC enquiry is simply a matter of proving that the original tax return or claim was correct.

That is only part of the picture.

The way the enquiry is handled can be just as important as the technical position itself. A sound tax position can become harder to defend if the evidence is incomplete, the explanation is unclear, correspondence is poorly managed, or the taxpayer and adviser do not identify what HMRC is actually testing.

There are indeed ways to handle HMRC tax enquiries. Having been on the inside, conducting numerous types of tax enquiries, investigations, and checks, I've seen how quickly things can go awry, often through no fault of any individual. First important thing is understanding what your rights are in this situation.

Remember that opening letter I mentioned at the outset above? Well, it should have enclosed with it an HMRC factsheet, explaining the nature of the check and the taxpayer’s rights and obligations in the process.

That factsheet matters.

HMRC’s own guidance makes clear that taxpayers should understand their rights and obligations when they are the subject of a compliance check. HMRC also publishes a collection of compliance check factsheets, including CC/FS1a: About compliance checks, which taxpayers and advisers should read carefully when a check begins.

In our experience, the first mistake many people make is to treat the enquiry as a routine administrative exchange. If a process can take around 8 months to conclude, then that should not be considered as “a routine administrative exchange."

Second thing is understanding where things can go wrong, and having deep insight into the entire process only comes with experience.

This does not mean HMRC is always right. It does not mean HMRC is always wrong. It means the enquiry needs to be managed carefully from the start.

The practical question is not simply:

"Are we right?"

It is also:

"Can we evidence the position clearly, answer HMRC’s questions properly, and protect the taxpayer’s procedural position at the same time?"

That is where many enquiry problems begin.

Why experience matters

Tax enquiry work requires a particular blend of skills.

Technical tax knowledge matters. So does an understanding of HMRC powers, information requests, statutory time limits, penalties, appeals, internal review, tribunal procedure and taxpayer safeguards.

It is also important to understand how HMRC may approach risk, behaviour, evidence and credibility.

This is why businesses and advisers should be careful when choosing enquiry support.

It is reasonable to ask any adviser about their relevant tax qualifications, enquiry experience and the type of HMRC work they have handled. It is also reasonable to ask for evidence of that experience, where appropriate.

The same applies where someone describes themselves as ex-HMRC.

HMRC experience can be valuable, but not every HMRC role involves conducting full enquiries, managing complex disputes, handling technical arguments or preparing cases that may ultimately move towards tribunal. The relevant question is not simply whether someone worked at HMRC. It is what kind of HMRC work they actually did.

Equally, in my 40 years of engaging with firms that deal with HMRC enquires, standards can vary. While I have encountered some highly skilled professional tax agents and accountants in enquiries, they are, regrettably rare, and not always the well-known names. In tax enquiries, your reputation hinges on your latest HMRC tax enquiry; in effect, you are only as good as your last HMRC Tax Enquiry.

A former HMRC background may be useful. It is not, on its own, proof of enquiry expertise. Likewise, the name and size of the firm you engage.

Where enquiries can go wrong

The questions I am asked the most are these two:

1. Does HMRC make mistakes in their enquiry checks, and can I use that to get my client out of trouble?

   
   

2. Where do they make mistakes the most?

   
   

The short answer to the first question is a definite “Yes, mistakes happen daily.” With around 70 million interactions, occasional slip-ups are inevitable. As I mentioned, HMRC tax enquiries are complex, and HMRC officers are only human.

Any calls for simplifying HMRC tax enquiries are a pipe dream. Tax can be, and is, very complicated. Consequently, the process for assuring and checking compliance with tax rules must reflect the complex nature of the tax or duty being investigated.

Experienced, fully tax-trained HMRC enquiry inspectors rarely make mistakes when conducting their enquires. When I started, the average length of experience in this type of work was between 10-15 years. Wisdom truly flourishes around the five-year mark in tax enquiry work. Now, the average level of experience for many HMRC enquiry officers is between 18 months to two years.

HMRC enquiries are detailed pieces of work. Mistakes and misunderstandings can arise on both sides.

Common pressure points include:

• Incorrectly opening an enquiry under the relevant tax legislation.

• Misapplying or incorrectly referencing the rules.

• Incorrect assumptions about the facts.

• Failing to fully understand the information provided.

• Making procedural mistakes.

• Information requests that are too broad, unclear or misunderstood.

• A failure to identify the precise issue under enquiry.

• Incomplete records.

• Poorly prepared explanations.

• A mismatch between what HMRC has asked and what the taxpayer has provided.

• Procedural errors.

• Escalating correspondence before the real issue has been understood.

These points require careful handling.

Now, a procedural mistake by HMRC will not automatically bring an enquiry to an end. In many cases, HMRC may be able to correct or move past an error. Equally, taxpayers and advisers can weaken their own position by responding too quickly, too defensively or without understanding the legal and evidential context.

The aim should not be to look for shortcuts.

The aim should be to understand the issue, control the flow of information, provide accurate evidence and preserve the taxpayer’s rights.

The R&D enquiry problem

HMRC has published its approach to R&D tax reliefs and has identified error and fraud as a significant concern in this area. HMRC has also strengthened the claim process, including the requirement for additional information to support claims. For many companies, this has changed the practical risk profile of making and defending an R&D tax relief claim.

An R&D enquiry is not simply about whether a project sounds innovative.

HMRC will usually want to understand the scientific or technological uncertainty, the competent professionals involved, the work undertaken, the costs claimed and the evidence supporting the claim.

That can create difficulties where the original claim was prepared without enough technical analysis, where the company cannot explain the uncertainty clearly, or where the records do not support the costs claimed.

The additional information form is now a central part of the claim process. HMRC guidance says it must be submitted before, or on the same day as, the Company Tax Return containing the claim. Some companies may also need to notify HMRC in advance that they intend to claim. These are not minor administrative points. They affect whether a claim is properly made and whether HMRC has the information it expects when reviewing the claim.

The challenge in an R&D enquiry is often evidential.

Can the company explain what advance in science or technology was sought?

Can it identify the uncertainty?

Can it show how the work attempted to resolve that uncertainty?

Can it connect the technical work to the expenditure claimed?

Can the claim be understood by someone outside the business?

This is where many disputes become difficult. The company may genuinely believe valuable development work took place, but belief is not enough. The claim needs to be evidenced in a way that addresses the statutory and HMRC enquiry questions.

The communication risk

Written exchanges can be efficient and HMRC has mandated that R&D enquiries in SME population are conducted entirely by correspondence.

However, correspondence-based enquiries can create particular problems, and for R&D enquiries conducted by correspondence alone, more difficulties can arise for several reasons.

First, a taxpayer may think they have answered the question. But if the answer is poorly written, not clear or incomplete in some way, HMRC may think the response has avoided answering the question. Equally, an adviser may be trying to explain the technical position while also managing incomplete client records, commercial pressures and HMRC deadlines. This can result in a follow up question from the caseworker seeking either a response, or a fuller response and/or clarification.

In the case of R&D enquiries in SME population, conducted entirely by correspondence, the caseworkers are not named in the letters issued. This makes any attempts at building any meaningful rapport and understanding almost impossible.

Despite the opening observation in this section that “written exchanges can be efficient”, the opposite can also be true. As explained above, enquiries conducted entirely by correspondence can create greater scope for delay and misunderstanding.

In the example given above, it is assumed that is concerned a relatively simple issue with a prompt exchange between HMRC and the taxpayer over the course of two months to complete. The same pattern may then be repeated as further issues arise or as additional points remain unresolved. These issues may be more complex and/or nuanced, resulting in a greater number of exchanges being required, each once taking successively longer to complete. Causing the enquiry to become unnecessarily prolonged.

Then there are the R&D enquiries in SME population conducted by correspondence which are usually handled across a number of large, geographically dispersed teams. This increases the potential for inconsistency, particularly where several HMRC caseworkers are involved at different stages of the enquiry.

Individual officers on these teams may deal with a case only once, picking up actions from a predecessor without having sufficient time or background knowledge to assess fully whether the earlier actions were correct, relevant or appropriate to the issues under consideration. This can result in a form of collective 'positional thinking'.

By this I mean, one party becomes fixed on defending a particular stance rather than examining the underlying facts, evidence and reasoning objectively.

For example, I would see this in enquires where either the taxpayer, adviser or HMRC R&D caseworker had decided early on in the process that their interpretation is correct. After that, they would assess every new point through that lens. The discussion then became centred solely on protecting that position, rather than resolving the enquiry properly.

This positional thinking is prevalent where HMRC caseworkers are required to follow a rigid, task-based process, designed to move the enquiry forward quickly. Individual officers may deal with a case only once, picking up actions from a predecessor without having sufficient time or background knowledge to assess fully whether the earlier actions were correct, relevant or appropriate to the issues under consideration.

The irony is that, in seeking to reduce delays in correspondence-only R&D enquiries, HMRC may inadvertently have embedded a degree of positional thinking within the process. The risk is particularly acute where caseworkers are required to continue work started by a predecessor based in a different geographical location, while operating within tightly controlled, time-limited and task-based procedures designed to move enquiries forward quickly. In those circumstances, the process may encourage officers to proceed from an established but potentially flawed position, rather than pause to verify the accuracy or relevance of earlier HMRC actions or reconsider the issue fully in light of new explanations, evidence or context.

This is why structure matters.

Before responding, it is worth asking:

• What exactly has HMRC asked?

• What issue sits behind the question?

• What evidence already exists?

• What evidence is missing?

• What legal or procedural point needs to be protected?

• What should not be said until the facts have been checked?

• That discipline can prevent a manageable enquiry from becoming a more serious dispute.

Six practical points for taxpayers and advisers:

1. Stay calm and positive:

   
   

   This is easier said than done.

   
   

   Tax enquiries are stressful, but they don't all have to be negative.

   
   

   I recall one individual who actually welcomed an HMRC enquiry. They saw it as an opportunity to identify and correct any bookkeeping issues, potentially reducing future accountancy costs. As it turned out, their records were in good order, with only minor errors and no additional tax or penalties to pay. In their case, the glass-half-full approach was justified.

   
   

   So, don’t panic. An enquiry does not automatically mean wrongdoing. HMRC may open a check for a range of reasons, including risk indicators, random selection, sector activity, claim profile or concerns about a particular issue.

   
   

   The first step is to read the opening letter carefully. Identify the tax, period, return, claim or transaction under review. Then check which HMRC factsheets have been provided or referred to.

   
   

   Do not ignore those factsheets. They explain important parts of the process, including rights, obligations and potential penalty issues.

   
   

2. Understand the procedural position

   
   

   Before responding in detail, understand the legal and procedural framework.

   
   

   That may include the type of enquiry, the statutory basis for HMRC’s request, the time limits, the taxpayer’s rights of appeal, the possibility of internal review, and the circumstances in which an information notice may be challenged.

   
   

   Asking reasonable questions, in a professional manner, about why a document or particular information is required, or why an action has been taken during an enquiry, does not, in itself, amount to obstruction. Nor does raising a legitimate challenge professionally and constructively.

   
   

   Where such questions are relevant and raised for proper reasons, they form part of a taxpayer’s reasonable efforts to understand the basis, scope and conduct of the enquiry. This may include asking HMRC to explain the purpose of a request, its relevance to the matters under enquiry and, where appropriate, the legal or procedural basis on which it has been made.

   
   

   An HMRC caseworker should not treat a taxpayer or adviser as obstructive merely because they seek clarification or challenge a request. Subject to any applicable legal, confidentiality or operational restrictions, the caseworker should be able to provide a clear and sufficiently detailed explanation of why the information is required or why the action has been taken.

   
   

   Ultimately, the aim is to ensure that all parties clearly understand the relevant issues and the reasons for HMRC’s requests, so that the enquiry is handled properly and can progress without avoidable delay.

   
   

3. Identify the real issue early

Many HMRC enquiries become more difficult than necessary because too much time is spent responding to surface-level questions rather than identifying the underlying issues at an early stage.

An enquiry can impose a substantial burden on a business, particularly where the key points are not clarified and addressed promptly. The associated demands on management time, staff capacity and professional costs can quickly escalate. There is also a real risk that the enquiry will draw attention and resources away from the day-to-day operation of the business.

A better starting point is:

"What is HMRC really testing?"

In an R&D enquiry, that may be the existence of qualifying uncertainty, the competence of the professionals involved, the boundary between routine work and qualifying activity, or the link between the costs claimed and the project work.

In a business tax enquiry, it may be the reliability of records, the treatment of income, the nature of expenses, the commercial purpose of a transaction or the behaviour behind an error.

Once the real issue is clear, the response can be more focused.

4. Expect the Check to find errors

Take an objective and healthy approach to the HMRC check, on the basis that it may identify errors.

Remember that no accounting or tax process is entirely free from risk, and genuine mistakes can occur during a financial year.

Where an error is found, the priority is to establish precisely how it arose, whether reasonable care was taken and whether the evidence shows that the error was neither deliberate nor concealed.

Describing an error as “innocent” is not enough. The explanation must be supported by the underlying records, the relevant facts and a clear account of the steps taken at the time.

This can become more difficult where the issues are technically complex or are not properly understood from the outset.

Suitably qualified and experienced professional support is therefore essential to protect the taxpayer’s position and ensure that HMRC receives an accurate, properly evidenced response.

5. Try and build a professional rapport and keep communication professional

Where an enquiry is not being handled by correspondence alone and direct interaction with the caseworker is possible, you should engage with them professionally. Doing so can help establish a constructive working relationship and support the orderly progression of the enquiry.

Combative correspondence rarely helps.

That does not mean conceding points that are unsupported or properly open to challenge. It means answering legitimate questions clearly, correcting misunderstandings firmly and maintaining a professional tone throughout.

Where a caseworker has made an error or misunderstood a material point, identify the issue respectfully, explain the correct position professional and support that explanation with relevant evidence and clear reasoning.

HMRC officers/caseworkers are more likely to understand a taxpayer’s position where the response is organised, evidenced and proportionate.

A good response does not simply say:

"The taxpayer is correct."

It explains why, shows the evidence, and deals with the issue HMRC has raised.

Consider this. Adopting a combative approach or making the enquiry unnecessarily difficult will prompt the caseworker to seek support from a more experienced or technically specialised colleague. This could lead to closer scrutiny and make the enquiry more demanding than it might otherwise have been.

Engaging proactively with the caseworker, clarifying what is reasonably required and providing clear, complete information promptly is generally the most effective way to keep the enquiry focused and progressing constructively.

6. Take advice before substantive engagement

Never go it alone.

It is possible to deal with an HMRC enquiry without professional assistance.

However, based on my experience as a former HMRC caseworker, I would not advise anyone to handle a substantive enquiry entirely on their own.

It is generally sensible to obtain professional advice before entering into detailed discussions with HMRC or submitting a written response on a material enquiry issue.

This is not because HMRC officers are necessarily trying to catch people out. It is because tax enquiries can become complex very quickly, and the difficulty does not always lie in the tax rules themselves.

It may arise from the procedure being followed, the way the rules have been interpreted or applied, a misunderstanding of the relevant facts, or weaknesses in the supporting records and evidence. In some cases, several of these factors may be present at the same time.

A rushed explanation can create unnecessary confusion. An incomplete response may prompt further questions, while a poorly framed answer can make an otherwise defensible position appear uncertain.

Taking advice at an early stage helps ensure that the facts are properly understood, the relevant issues are identified, and the response is presented clearly and accurately.

The earlier the enquiry is structured properly, the easier it usually is to manage.

The small but important points

Many people think an HMRC enquiry is won or lost on the technical tax answer alone.

In practice, the position is often wider.

Can the facts be explained clearly?

Does the evidence support the position taken?

Has HMRC’s request been understood?

Has the taxpayer’s procedural position been protected?

Has the response helped HMRC reach the right conclusion, or has it created more uncertainty?

That is the real issue.

An HMRC enquiry is not just a test of the tax position. It is a test of the records, the explanation, the evidence and the judgement used in managing the process.

Final thought

An HMRC enquiry should not be ignored, rushed or treated as routine correspondence.

Handled well, it can often be brought under control. Handled poorly, even a defensible position can become more difficult, more expensive and more stressful than it needed to be.

The starting point is simple.

Understand the issue. Read the HMRC guidance. Gather the evidence. Manage the process. Take advice before making substantive responses.

That approach will not guarantee a particular outcome. No adviser can properly promise that.

It does, however, give the taxpayer a better opportunity to deal with the enquiry in a structured, credible and professionally managed way.

When I conducted HMRC enquiries, I found that knowledgeable tax professionals who were open and transparent usually managed both their client’s involvement and the enquiry process efficiently.

They ensured that the relevant documents were provided and that any necessary meetings were arranged promptly. This often enabled me to complete the check in around half the time it might otherwise have taken. Where penalties arose, the evidence they provided was usually sufficiently detailed and tested to allow me to consider any available mitigation properly and within the rules. In my experience, that outcome was largely due to the agent’s professionalism and effective management of the enquiry.

HMRC enquiries can be costly before any additional tax liability is established. They consume valuable time and can escalate quickly if handled poorly. High-quality professional advice may cost more at the outset, but, in my experience as a former HMRC caseworker, rushed or inadequate support often led to far greater costs. When HMRC starts asking questions, cheap advice can become the most expensive decision you make.

(Disclaimer: This article provides general commentary only and should not be treated as tax advice. Specific advice should be taken before acting on any tax, compliance, enquiry or dispute issue.)