#7 Spring 2026

UK: Mandatory Registration of Tax Advisers With HMRC

Simon Martin Head of UK Technical Services View profile

From 18 May 2026, tax advisers who are paid to interact with HM Revenue and Customs (HMRC) on behalf of clients will be required to register with HMRC and meet minimum professional standards.

HMRC has indicated that the new register will strengthen its ability to monitor adviser behaviour and exclude those who fail to meet required standards, forming part of a wider effort to raise standards in the tax advice market.

Who Is Considered a Tax Adviser?

The definition of a tax adviser is intentionally broad. It covers:

Any person or organisation who, in the course of a business, assists other persons with their tax affairs.

For these purposes, assisting a person with their tax affairs includes any of the following activities:

  1. Advising another person in relation to tax
  2. Acting, or purporting to act, as an agent on behalf of another person in relation to tax
  3. Providing assistance with any document that is likely to be relied upon by HMRC to determine another person’s tax position

A person may still fall within the definition of a tax adviser even if:

  • They are appointed indirectly at the request of someone other than the client, or
  • They carry out activities in addition to assisting clients with their tax affairs

The registration requirement also applies to firms and individuals based overseas where they interact with HMRC.

Requirement To Register and Consequences of Non-Compliance

A person or organisation meeting the definition of a tax adviser must not interact with HMRC unless registered.

The registration obligation applies to the legal entity that interacts with HMRC. Individual employees will not need to register separately, although firms must provide details of relevant individuals as part of the process. Registration will take place through an online system, which is currently under development.

For these purposes, interacting with HMRC includes:

  • Contact by telephone or email
  • Sending messages via HMRC websites or portals
  • Filing returns, claims, notices or other documents, electronically or otherwise
  • Any other form of communication with HMRC

Tax advisers who do not hold an Agent Services Account (ASA) will generally be required to register from 18 May 2026, although deadlines may vary depending on the nature of the activity. At the time of writing, the deadline for overseas tax advisers has not yet been confirmed.

Failure to register may result in a compliance notice being issued. Continued interaction with HMRC after a compliance notice has been served can lead to financial penalties, which may apply to the firm and/or the individual.

Exceptions To the Registration Requirement

Certain activities and individuals are exempt from the registration requirement. These include, but are not limited to:

  • Providing tax advice services free of charge, such as through a charity
  • Individuals who interact with HMRC solely in the course of business carried out by their employer
  • Individuals who provide payroll or accounting software and fall within the definition only for that reason
  • Interactions with HMRC in relation to customs duties, excise duties or import VAT
  • VAT representatives and certain group undertakings
  • Interaction with HMRC in connection with an appeal before a court or tribunal relating to an HMRC decision

Standards Advisers Must Meet

Although the draft Finance Bill legislation does not require advisers to be members of a professional body, registration is conditional on meeting defined standards.These include confirmation that the adviser:

  • Has no outstanding tax returns or amounts due
  • Is not subject to an HMRC decision refusing to deal with them
  • Is not subject to sanctions under tax anti-avoidance measures
  • Is not disqualified from acting as a director in the UK or overseas
  • Is not insolvent
  • Has no unspent convictions for fraud or tax-related offences

In addition, advisers must:

  • Be registered for anti-money laundering (AML) supervision, and
  • Ensure that both the adviser and each senior manager meet HMRC’s published standards for dealings with HMRC

What Advisers Should Do Now

Advisers should consider whether their activities involve interaction with HMRC that will trigger the new registration requirement. Early review is advisable, particularly where services are provided across borders or through complex structures.

Failure to register, or to meet the required standards, may result in financial penalties and restrictions on future dealings with HMRC.

Further guidance is available from professional bodies, including the Association of Tax Technicians (ATT) and the Chartered Institute of Taxation (CIOT).

The current draft legislation can be accessed here:
https://www.gov.uk/government/publications/modernising-and-mandating-tax-adviser-registration-with-hmrc/draft-legislation-accessible-version

Key Takeaways for Advisers

  • Assess whether your activities fall within scope. Advisers who are paid to interact with HMRC on behalf of clients should review whether their services meet the broad statutory definition of a tax adviser.
  • Confirm registration requirements early. From 18 May 2026, unregistered advisers must not interact with HMRC, and registration applies at the level of the legal entity rather than individual employees.
  • Review cross-border arrangements. Overseas-based advisers interacting with HMRC are subject to the same requirements, and deadlines may differ depending on activity.
  • Check internal governance and standards. Advisers should ensure there are no outstanding tax liabilities, sanctions or disqualifications that could prevent registration.
  • Plan for operational change. Firms should prepare for the new online registration system, identify relevant individuals, and monitor further HMRC guidance on practical implementation.