UK Mandatory Tax Adviser Registration: What The New Guidance Means For In House And Asset Management Tax Teams

Key developments from HMRC’s guidance

1. Scope remains deliberately broad—and highly functional

The guidance confirms that a “tax adviser” includes any organisation or individual who, in the course of a business, assists another person with their tax affairs and interacts with HMRC.

“Assisting” is interpreted widely and includes:

• providing tax advice;
• acting (or purporting to act) as agent; and
• preparing documents relied on by HMRC. “Interaction” is equally broad, covering any communication with HMRC, including filings, emails, and digital submissions.

This reflects (and reinforces) the position set out in our earlier notes: the regime is defined by activity, not by professional status or how a team describes itself.

Note that it is the legal entity providing the service that must register. Individuals that are employed by a tax adviser business will not need to register (individuals will only need to register where they conduct business as a sole trader).

2. In-house exemption confirmed—but narrowly applied

The guidance confirms that businesses that provide tax advice to other entities within the same group as the advising entity are out of scope. The example is given of an in-house tax team that:

• prepares or files returns solely for its employer; and
• does not provide tax advice or services externally,

which will generally not require registration.

However, this is a narrow exemption and has not been broadened by the guidance, though in a nod to the ongoing discussions with industry bodies, the guidance does confirm that HMRC will add specific guidance and examples covering more complex scenarios in due course.

As things stand however, it reiterates that:

• a small amount of in-scope activity is sufficient to require registration (even where other activities do qualify for exemption). So, for example, even if the vast majority of a tax adviser’s activities would be within the group exemption, providing services to a single JV might still mean registration is required.
• Every entity which employs individuals providing a tax advisory function within a group structure must be separately considered and if necessary, registered.

Further, the examples of services that do not require registration do not include where tax advisory services are provided outside the group but as a matter of fact no fee is paid.

The guidance specifically refers to individuals advising family members and work done by charities or otherwise on a pro bono basis, but does not seem to contemplate that there may be circumstances where one party will agree to support the tax compliance of another but for no payment (a situation which can arise both in joint venture arrangements and also in the context of M&A where a seller might retain control of a target company’s tax administration for a period of time).

Helpfully the list of examples in the guidance is expressed to be non-exhaustive and HMRC’s Registration Checker frames this condition more broadly, asking only “Is your business paid for its tax services?” (which, according to HMRC, includes receiving gifts). A negative response to this question results in the Checker determining that “You do not need to register with HMRC” although this is caveated by the statement that “the results do not provide a formal decision by HMRC”.

3. Asset management structures remain in scope for now

The guidance does not introduce any special treatment for asset managers or private capital structures, beyond reconfirming that the financial service organisations without an ASA may delay registration to the period from 31 December 2026 – 31 March 2027.

This is significant. For many asset managers:

• fund vehicles are not “group undertakings”;
• investor-related tax work is common; and
• centralised tax functions frequently interact with HMRC across multiple entities.

It is understood that HMRC is liaising with industry regarding how the rules should be applied to financial services organisations, and further legislative changes may be introduced at a later stage. For now though, HMRC’s guidance reiterates that businesses may only rely on the financial services delay for implementation if they “solely” provide those services as part of a financial services business. Where a business carrying out financial services also carries out other services, it will need to consider if it is required to register in an earlier tranche.

Further, the legislation implementing the financial services organisation delay has not yet been finalised but HMRC’s Registration Checker states:

“Financial services activities:

• are regulated under the Financial Services and Markets Act 2000
• count as financial services even if you do not need Financial Conduct Authority (FCA) or Prudential Regulation Authority (PRA) authorisation, or your business operates outside the UK”.

This suggests that HMRC is planning to adopt a narrow approach to the organisations that can benefit from this deferral.

4. Focus shifts to registration mechanics and governance

Beyond scope, the broader guidance and related materials confirm that:

• registration is at the entity level, not individual level; 
• organisations must identify “relevant individuals” subject to suitability checks; 
• firms must meet ongoing minimum standards and conduct requirements. 

This reflects a clear shift in the regime: from definitional uncertainty to operational readiness. For businesses that been waiting (and hoping) for developments which would take them out of the regime, the publication of this guidance may indicate that they now need to reach a landing on whether registration is required and refocus efforts on planning for registration.

Practical implications for in-house and asset management tax teams

1. Many in-house teams are still within scope

Despite the in-house carve-out, organisations should assume they may be caught if they:

• interact with HMRC for non-group entities; or
• support fund, JV or investor structures.

A binary “in-house vs adviser” distinction is unlikely to be determinative. Those who believe themselves to be wholly within the (as yet unpublished) financial services deferral may have more time. 

2. Mapping exercises are now critical

Organisations should be mapping:

• which entities they act for;
• where HMRC interactions occur; and
• which functions or individuals are involved.

This may reveal that registration is required for one or more different entities within the organisation.

3. Outsourcing is not a silver bullet

A key live issue (and one where there have been mixed messages) is whether outsourcing filing or HMRC interactions can avoid registration.

While the legislation suggests this may be possible in theory, HMRC has indicated to certain industry bodies that “interaction” should be interpreted very broadly (extending to payments), making an outsourcing model challenging in practice. 

The recently published manual confirms this view – stating “Interaction applies regardless of whether the interaction is routine, one-off, or undertaken as part of a wider professional service that is not related to tax advice.” An example in a conveyancing context is provided – “if filing and payment of Stamp Duty Land Tax are split (for example where filing is outsourced), there will be a registration requirement for both businesses.”

4. Governance and HR implications are emerging

The requirement to identify “relevant individuals” and meet suitability standards introduces:

• governance considerations (who is responsible as a matter of fact, not just as a matter of reporting lines?);
• HR implications (fit and proper tests, disciplinary frameworks); and
• documentation and monitoring requirements.

Further, for any businesses not currently under AML supervision who now need to obtain such status as a precondition for registration under the MTA, this could present a significant additional compliance burden (with associated costs).

This is a meaningful shift for organisations not historically considered or regulated as “tax advisers.” 

Expert insight: direction of travel

The latest guidance reinforces three broader themes:

• HMRC is prioritising behavioural regulation over professional boundaries
  The regime is designed to capture activity—particularly where HMRC interaction occurs—rather than traditional advisory roles.
• In-house and asset management sectors remain a key area of unintended breadth
  Despite industry engagement and indications that further relaxations may come in the future, there has been no material narrowing to date.
• Implementation risk now outweighs interpretive uncertainty
  The immediate challenge for most organisations is no longer “are we in scope?” but “how do we comply?”

Key takeaways

• The new HMRC guidance largely confirms (rather than limits) the broad scope of the MTA regime.
• In-house exemptions are narrow and will still not apply to many asset management and multi-entity structures.
• Asset managers (especially those who may not be able to comfortably rely on the financial services deferral) remain particularly exposed, given the prevalence of non-group entities.
• Outsourcing strategies may not remove risk entirely.
• The priority has shifted to practical implementation: mapping, governance and registration readiness.