Mandatory registration as a tax adviser with HMRC from May 2026

17 February 2026

Last updated: 17 February 2026

Susan Cattell
Head of Tax Technical Policy, ICAS

From May 2026, anyone who interacts with HMRC on behalf of clients about their tax affairs will need to register with HMRC. HMRC has issued initial guidance on how and when tax advisers will need to register, and the standards they will need to meet.

Mandatory registration of tax advisers with HMRC

Following a consultation in 2024, the government announced that all tax practitioners who wish to interact with HMRC on behalf of clients will need to register with HMRC. Legislation to implement this decision is included in the current Finance Bill.

The government views this as a step towards raising standards in the tax advice market. It has stated that the requirement will be supported by the necessary investment to ensure HMRC’s registration services for practitioners are easy to use.

HMRC has published initial guidance on registration, the timeline for registering and the conditions advisers will need to meet. The key points are summarised below. Advisers should review the guidance for more detailed information.

ICAS is involved in ongoing discussions about implementation and guidance. Please send us any queries or feedback about registration (contact details at the end of this article).

Who will need to register?

Anyone who interacts with HMRC about someone else’s tax affairs and is paid to do so, will need to register with HMRC as a tax adviser.

Interaction with HMRC includes:

Phone, post or email.
Messages through the GOV.UK website or HMRC app.
Sending returns, claims or other documents.

The legal entity that interacts with HMRC must register. Individual employees will not need to register separately, but HMRC will carry out checks on certain people within the registered business.

The business will need to register even if:

It does not view itself as a tax adviser, or describe its work as tax advice.
It works as a registered sole trader.
Helping people with their tax affairs is not its main business function.
It only interacts with HMRC on behalf of one client.
It is based outside the UK.

Exemptions from registration

Businesses will not need to register with HMRC if they:

Are an employer or in-house tax team, running payroll for their own staff.
Only deal with tax affairs within their own company group.
Provide tax advice services for free (for example, charitable services or helping friends or family with tax).
Interact with HMRC on behalf of taxpayers because the law requires it, even if they get paid (for example, insolvency practitioners, some pension or investment firms).
Must interact with HMRC in response to a request for information.
Provide payroll, accounting or tax software for others to use, but do not interact with HMRC.

They will also not need to register if they only interact with HMRC:

On customs or import VAT.
As a VAT representative (appointed to handle VAT matters for a business).
As a Northern Ireland tax representative (appointed by a business outside the UK to manage certain Northern Ireland-specific tax obligations).
As a UK representative for Vaping Duty (appointed by an overseas business to deal with specific UK tax matters).
To represent a client in appeals to a court or tribunal.

Conditions advisers must meet

Businesses will need to meet certain conditions in order to have an Agent Services Account (ASA), which will be the mechanism for registration with HMRC. Some of the people who work for the business (‘relevant individuals’) must also meet the conditions.

Businesses will need to review HMRC’s guidance carefully to understand who will be treated as ‘relevant individuals’. This will depend on how many ‘officers’ the business has. Officers include directors, partners and any equivalent roles (including in overseas companies).

The registration conditions

The business must:

Provide evidence of being supervised for anti-money laundering.

The business must not:

Have any relevant outstanding tax returns or unpaid tax (unless covered by a payment plan).
Be subject to a decision by HMRC refusing to deal with it.
Be subject to an anti-avoidance sanction or a stop notice.
Have any relevant unspent convictions for fraud or tax offences.
Be formally insolvent.
Be suspended or permanently banned from registering with HMRC.

Relevant individuals must also not be disqualified from acting as a director either in the UK or overseas.

When to register

From 18 May 2026, HMRC will introduce an online registration system for ASAs. The requirement to register will be introduced in stages.

Anyone who already has an ASA will not need to register again. HMRC will contact them through their ASA when it needs more information from them to check whether they meet the conditions outlined above.

Those who do not have an ASA will need to register for one from 18 May 2026, unless one of the following applies:

Those who already have a Self Assessment or Corporation Tax account will need to register from 18 August 2026.
Those who only provide third-party payroll services on behalf of clients and do not interact with HMRC in any other way will need to register from 18 November 2026

It will be possible to use the online service to register from 18 May, even if registration is not required until a later date.

Advisers will have 3 months from the date they need to register to apply for an ASA. They can continue to interact with HMRC on behalf of clients:

During these 3 months.
While HMRC considers their application.

Sanctions

There will be sanctions, if advisers fail to register but continue to interact with HMRC on behalf of clients. Once registered, they must also continue to meet the standards. There will be sanctions for failing to do so.

HMRC is planning to issue further guidance on sanctions (and appeals). These will be covered in a later article.

Let us know what you think

We respond to tax consultations and calls for evidence and attend meetings with HMRC at which service levels, delays and other issues you raise with us are discussed. We welcome input from members to inform our work; email us to share your insights and feedback.

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