HMRC Mandatory Tax Adviser Registration, MTAR, and R&D Claims: A Mark of Quality?

In my last article on tax adviser registration: Adviser Accountability and the RDEC Claims Regime, I looked at how HMRC is increasing visibility over advisers involved in R&D claims and why this means businesses should pay closer attention to who is preparing their claims. In this article I explore how HMRC's Mandatory Tax Adviser Registration, MTAR, may improve transparency, but also raises the risk that R&D claimants, hiring specialist advisers, may assumes registration is evidence of competence and how to mitigate this risk.

The introduction of MTAR has understandably focused attention on compliance. Much of the early discussion has centred on practical questions: who needs to register, what information must be provided and how advisers will meet the new requirements.

However, as HMRC's internal manuals have emerged, including MTAR10000 on scope and registration requirements and MTAR20400 on identifying "Relevant Individuals", a more significant issue is becoming apparent. The real impact of MTAR may not be the registration process itself, but what it reveals about governance, accountability and the delivery of specialist tax advice.

For companies claiming Research and Development Expenditure Credit (RDEC) or Enhanced R&D Intensive Support (ERIS), that distinction matters.

Why Mandatory Tax Adviser Registration Is Not a Quality Mark

One of the risks arising from MTAR is that businesses may begin to view registration as a form of accreditation. It is easy to see why. If HMRC requires advisers to register, many company directors may assume that registration itself provides reassurance about competence and quality.

That would be a mistake.

The purpose of MTAR is not to certify technical expertise in R&D tax relief. Nor is it designed to distinguish between advisers with extensive experience in software development, engineering, life sciences or manufacturing and those with only a limited understanding of the technical and tax complexities involved.

Registration establishes a regulatory baseline. It helps HMRC identify those providing tax advice and creates greater transparency around the individuals responsible for those activities. What it does not do is assess whether an adviser has the experience, technical capability or sector knowledge required to prepare and defend a robust R&D claim.

For Finance Directors and CEOs, this means adviser selection cannot stop at confirming whether a firm has successfully registered. The more important questions remain the same: who is overseeing the work, what expertise supports the claim and how are technical and tax judgements being made?

What MTAR Reveals About How Advice Is Delivered

One of the more interesting aspects of MTAR20400 is HMRC's focus on identifying "Relevant Individuals". The guidance places emphasis on those who direct, control or oversee tax advice activities, rather than simply those who carry out day-to-day work.

This reflects a broader principle: HMRC is interested not only in the advice being provided, but also in how that advice is governed.

That distinction is particularly relevant in the R&D tax relief market, where claim preparation often involves multiple parties. A company's accountant may engage a specialist R&D consultancy. The consultancy may rely on technical interviewers, sector specialists, tax reviewers or external contractors. In some cases, elements of the process may be outsourced or delivered through white-label arrangements.

None of these operating models are inherently problematic. Indeed, specialist expertise is often essential when assessing complex R&D projects. However, the guidance highlights the importance of understanding who is ultimately responsible for the methodologies, standards and judgements that underpin a claim.

For claimant companies, the key issue is not whether external specialists are involved. The key issue is whether there is clear accountability for the advice being delivered.

Governance Is Becoming Even More Important

Viewed alongside recent developments in the R&D regime, MTAR appears to form part of a wider trend towards increased transparency and accountability.

The introduction of the Additional Information Form, the requirement to identify a senior officer within the claimant company, increased compliance activity and now adviser registration all point in a similar direction. HMRC is seeking greater visibility over both the claims being submitted and the people involved in preparing them.

For advisory firms, this may place greater emphasis on governance structures, quality control processes and clearly defined responsibilities. Firms will need to consider who exercises oversight of tax advice activities and whether their operating models provide sufficient clarity around decision-making and accountability.

This does not mean that smaller specialist firms are disadvantaged. Many boutique R&D advisers have exceptionally strong technical expertise and robust internal controls. Equally, larger organisations are not automatically better positioned simply because of their size.

The more important issue is whether the firm can demonstrate a clear framework for managing risk, maintaining quality standards and overseeing the advice it provides.

A New Due Diligence Question for Claimants

Historically, businesses choosing an R&D adviser have often focused on claim value, fees, sector experience and testimonials. Those factors remain important, but MTAR introduces another consideration.

Companies should seek to understand how their adviser delivers and governs its services.

Who ultimately takes responsibility for technical and tax decisions? How are external specialists supervised? What review processes exist before a claim is submitted? How does the firm ensure consistency and quality across different projects?

These questions may prove more valuable than simply asking whether a firm has registered with HMRC.

Looking Beyond Compliance

MTAR will undoubtedly create additional administrative obligations for advisers. Yet its longer-term significance may be cultural rather than procedural.

The regime encourages a shift in focus from individuals preparing reports to the systems, controls and governance structures that support the advice being given. For businesses making R&D claims, that should be viewed as an opportunity to look beyond registration and examine how advice is actually produced.

In the years ahead, the strongest advisers are unlikely to be those who merely satisfy the registration requirements. They are more likely to be those who combine technical expertise with clear governance, robust review processes and transparent accountability.

For companies seeking to make sustainable and defensible R&D claims, that distinction may become increasingly important.

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