Mandatory Registration of Tax Advisers

Introduction

Finance Act 2026 introduced a mandatory registration scheme for tax advisers that interact with HMRC on behalf of clients. The scheme forms part of a wider package of measures intended to raise standards within the tax profession and increase accountability amongst those providing tax advisory services.

Consequences for being unregistered can include being unable to interact with HMRC and financial penalties. Details of persons who have received a financial penalty or received an ineligibility order under these registration provisions may be published by HMRC.

This note provides a high-level overview of the new registration requirements and the practical considerations relevant for both Family Offices and other individuals who provide tax services.

What is the mandatory registration of tax advisers?

The new scheme requires certain tax advisers who interact with HMRC on behalf of clients to register with HMRC. Both UK and non-UK advisors are within the scope of these rules. Broadly, registration is required where a person or organisation:

• Interacts with HMRC in relation to another person’s tax affairs; and
• Is paid for providing that service.

For the purposes of the legislation, a tax adviser includes organisations or individuals that:

• Advise clients in relation to tax;
• Act on behalf of clients in relation to tax matters; or
• Assist with preparing documents, such as tax returns, that HMRC may rely on when determining a person’s tax position.

The legislation applies based on the activities being undertaken rather than based on how an organisation describes itself. HMRC’s guidance makes clear that businesses should consider all activities they undertake rather than simply their primary business function.

From a Family Office perspective, this will be relevant where services include direct interaction with HMRC on behalf of family members, trusts or other structures. Family Offices operating through multiple entities, trusts and investment structures should consider which legal entity is responsible for interacting with HMRC and whether any registration requirements may arise.

Key registration requirements

The key features of the registration regime are summarised below:

• HMRC interaction: HMRC adopts a broad interpretation of interaction, including where an individual attempts to do any of the following on behalf of another person in relation to tax:
  • Contacting HMRC by telephone, post or email;
  • Sending a message to HMRC through the GOV.UK website or HMRC app;
  • Filing returns, claims, notices, disclosures, or other documents with HMRC;
  • Any other communication with HMRC concerning another person’s tax affairs;
  • HMRC’s guidance states that making payments to HMRC is an interaction that would trigger a registration requirement. This is particularly relevant for Family Offices that make tax payments on behalf of family members, trusts or other structures.
• Registration applies at legal entity level: The requirement to register applies to the legal entity providing the service rather than individual employees.
• Independent assessments: Every entity that provides services must independently assess its position: registration by one entity does not automatically cover other entities within the same structure.
• Relevant individuals: In addition to the business meeting requirements, certain senior individuals who manage or oversee tax advisory activities (“relevant individuals”) must meet prescribed standards.

HMRC’s focus is on individuals who exercise strategic control or oversight of tax advisory activities rather than those simply undertaking day-to-day compliance work. In practice, Family Offices should determine who has strategic responsibility for tax advisory activities or HMRC interactions, as these individuals may need to be identified as relevant individuals for registration purposes. If several people share responsibility, Family Offices should consider how many individuals meet this definition.

• Registration conditions: To obtain and maintain registration, both the entity and relevant individuals must satisfy a range of conditions. These include requirements relating to:
  • Compliance with their own personal tax obligations, including filing and paying tax on time;
  • Insolvency status;
  • Anti-avoidance sanctions;
  • Criminal convictions for relevant tax or fraud offences;
  • Compliance with HMRC’s Standard for Agents.

HMRC will monitor compliance after registration and may perform risk-based reviews.

• Suspension risk: Failure to satisfy registration requirements may result in registration being suspended or withdrawn. This could significantly restrict advisor’s ability to interact with HMRC on behalf of clients, resulting in operational and reputational consequences. Family Offices should therefore consider succession and contingency planning for relevant individuals, particularly where a change in personnel could affect compliance with the registration conditions.

Exemptions from the registration requirement

Statutory exceptions from the requirements apply to businesses that solely do one or more of the following:

• Providing tax or accounting software, including payroll software, for use by a client in relation to their own tax affairs;
• Services relating to customs duty, import VAT or excise matters;
• Acting as a VAT representative for a non-established taxable person;
• Acting as a National Insurance (NI) tax representative;
• Acting as a UK representative for vaping duty;
• Acting as an Import One Stop Shop intermediary;
• Intra-group tax advice, where advice is provided only to other entities within the same group;
• Activity relating to appeals before a court or tribunal;
• Interact with HMRC where required by law, for example as an insolvency practitioner or in certain regulated financial or pension scheme roles; or
• Interact with HMRC in response to a request for information.

Activities that are unlikely to require registration

HMRC’s guidance also gives examples of activities that are unlikely to require registration, including:

• In-house tax teams who only act for their employer;
• Informal family or personal support that is not provided by way of business;
• Free charity advice or other pro bono work that is not undertaken in the course of a business;
• General tax education or training that does not involve specific advice on a client’s circumstances or acting as agent; and
• Insolvency practitioners acting in a statutory office-holder capacity.

These examples are not exhaustive. Family Offices should consider whether any entity within their structure is being paid specifically to interact with HMRC on behalf of family members, trusts, or other group entities (rather than simply providing internal support) as this may trigger the registration requirements.

When advisers need to register

Registration is being introduced in stages. Each category of adviser generally has a three-month window in which to register. The relevant window depends on the adviser’s existing HMRC registration status and the nature of the services provided.

• 18 May 2026 to 18 August 2026: New tax advisers, and advisers interacting with HMRC without an Agent Services Account (ASA), Self-Assessment agent account or Corporation Tax agent account.
• 18 August to 18 November 2026: Advisers with a Self-Assessment or Corporation Tax agent account, but without an ASA.
• 18 November 2026 to 18 February 2027: Advisers who solely provide payroll services and do not have an ASA. An earlier window applies if wider tax services are provided.
• 31 December 2026 to 31 March 2027: Financial services organisations without an ASA.

A business can interact with HMRC during its registration window and while its application is being processed, provided the registration deadline is met.

HMRC’s expanding powers

Mandatory registration regime forms part of a wider trend towards increased HMRC oversight of tax advisers.

Historically, HMRC's role has largely focused on tax collection. Recent legislation increasingly places HMRC in the position of de facto regulator of the tax profession, with enhanced powers to investigate and sanction advisers whose conduct falls below expected standards.

While these measures are intended to address poor behaviour and aggressive tax avoidance, they potentially affect all advisers operating within the UK tax system.

Sanctionable conduct and HMRC investigations

HMRC's powers relating to sanctionable conduct have also expanded. The key points include:

• HMRC may investigate advisers suspected of engaging in sanctionable conduct;
• File Access Notices may be used to obtain access to client files, internal documents, tax records and communications;
• Disputes regarding notices may require formal legal proceedings;
• Penalties of up to 100% of the tax at stake may apply in certain circumstances.

Find out more…

This note reflects the law in force on 7 August 2026. This note does not cover all aspects of this subject. To find out more about any aspect of the above, please discuss with your usual Deloitte contact. If you do not have a usual contact, please contact Michelle Robinson (michellerobinson@deloitte.co.uk)