HMRC’s powers reform for tax advisers : A new enforcement era begins on 01/04/2026

From 01/04/2026, the tax advisory profession enters a new compliance landscape. HMRC’s powers will be significantly strengthened, changing when and how professional risk materialises for advisers.

Amendments to Schedule 38 of the Finance Act 2012 will permit HMRC to issue file access notices and impose penalties based on reasonable suspicion of non-compliance facilitation. Critically, this can occur without the need for tribunal approval. However, this not providing HMRC with “unfettered” power, it is just that any judicial oversight shifts from pre-approval to post-challenge.Nevertheless  this reform signals a move towards earlier intervention, fewer procedural checks, and more assertive enforcement. The reforms are primarily targeting high-risk and avoidance-facilitation behaviours, though collateral exposure risk does increase for mainstream firms.

Key legal changes from 01/04/2026

1. Lower threshold: Reasonable suspicion replaces legal determination
   HMRC will be entitled to act based solely on internal suspicion. This marks a departure from the current model, which depends on judicial findings. As a result, advisers may face scrutiny and reputational impact even while the client’s position remains unresolved or under appeal.
2. File access notices no longer require tribunal approval
   HMRC will no longer need to secure external judicial consent to access adviser files. Instead, approval must come from a senior officer not previously involved in the case. This aligns with the approach already used for financial institution notices under Schedule 36 of the Finance Act 2008approval. Although some internal oversight remains, any tribunal review, a key procedural safeguard, is now moved a post challenge stage.
3. Penalties linked to lost revenue, not fixed bands
   The existing penalty framework will be replaced. Penalties will be proportionate to the potential lost revenue, with no upper statutory limit. Repeat breaches may attract escalated sanctions. While cooperation may reduce the penalty, advisers could still suffer reputational harm long before any resolution.
4. Focus on facilitation, not intent
   The benchmark for liability will shift from dishonesty to deliberate facilitation. Advisers will not need to be shown to have acted with criminal intent. Instead, if earlier advice is reasonably suspected of having enabled non-compliance, it may trigger review. Corrective advice will not be penalised, but the risk window has clearly widened.
5. Increased use of public naming powers
   HMRC will continue to name advisers under powers from regimes such as POTAS and Follower Notices. This may occur regardless of the outcome of any client appeal or regulatory process. There is no statutory route for delisting once publication occurs. The reputational consequences may therefore be immediate and enduring.
6. Mandatory registration of tax advisers

     
Failure to register when required means:   

Broader scope and wider exposure

These powers will apply to both individuals and entities, including partnerships and corporates. Liability is no longer limited to the adviser giving the advice. Entity-level responsibility will be engaged. The definition of tax adviser will cover any person or business providing tax advice commercially, regardless of location or qualification.

Strategic consequences for professional practice

Leading professional bodies including ATT, CIOT and LITRG have emphasised the need for a reassessment of business models and risk frameworks. Key implications include:

• Earlier exposure to reputational and regulatory risk
• Reduced appetite for high-risk engagements or novel tax positions
• Increased insurance costs, driven by broader liability and scrutiny
• Greater reliance on precise documentation, clear disclaimers and rigorously defined scopes

Practical compliance from 2026 onwards

Firms should now prioritise preparations to meet these obligations. Actions may include:

• Introducing filters to identify and exclude high-risk clients at onboarding
• Clearly documenting scope, responsibilities and any limitations in each engagement
• Providing written justification for advice that departs from HMRC guidance
• Maintaining files in a state suitable for potential disclosure
• Preparing systems for registration and ongoing oversight from 01/04/2026

A shift towards earlier, internalised scrutiny

Perhaps the most significant change is the relocation of scrutiny from the judiciary to HMRC’s internal processes. Reasonable suspicion will now trigger enforcement measures that were once contingent on external review. This creates an environment where reputational and financial consequences may arise before any client outcome is known or tested.

This is not merely a procedural adjustment. It reflects a deeper change in enforcement logic. The question will no longer be whether an adviser was ultimately wrong. It will be whether HMRC believes the adviser’s conduct contributed to non-compliance. That belief alone may now be enough to justify intervention.
The real risk is not being a “promoter”. It is:

Loose documentation
Verbal advice without file notes
Taking aggressive positions without written rationale
Poor client onboarding
Weak engagement letters
Failure to evidence reasonable care
Not documenting departures from HMRC guidance

Under “reasonable suspicion”, poor file hygiene becomes a liability multiplier.

Conclusion: Accountability has moved upstream

The reforms taking effect from 01/04/2026 do more than recalibrate penalties or process. They redefine the timing and basis on which advisers are held accountable. Professional exposure will now occur earlier, be based on internal suspicion, and carry reputational weight irrespective of formal resolution.

In this new landscape, what matters is not just the technical accuracy of advice, but whether it stands up to scrutiny when HMRC starts asking questions. For many firms, that moment will arrive far sooner than before.