Registering with HMRC as a tax adviser: what began on 18 May 2026

acrenvo.com/guides/tax-adviser-registration-with-hmrc, last reviewed 25 October 2026

HMRC began registering tax advisers on 18 May 2026, with each group given its own window to register. GOV.UK says who counts: “If you interact with HMRC about someone else’s tax affairs and get paid for it, we consider you to be a tax adviser. This means you’ll need to register for an agent services account.” Registration is free and online. If you missed your registration window, or are new to the market, you should register now.

Tomasz is fictional. Tomasz works alone as a bookkeeper, keeping the records for a couple of dozen small businesses and landlords, and once a year sends a handful of their tax returns to HMRC. Tomasz has never thought of the work as tax advice, so a client’s question about whether Tomasz had registered with HMRC yet came as a surprise. This guide sets out what GOV.UK says about the new registration, who it reaches and what it asks for, so that someone in that position can tell where they stand.

Who has to register

HMRC’s test is about what you do, not the title you use. GOV.UK puts it like this:

If you interact with HMRC about someone else’s tax affairs and get paid for it, we consider you to be a tax adviser. This means you’ll need to register for an agent services account.

Interaction with HMRC includes:

• phone, post or email
• messages through the GOV.UK website or HMRC app
• making payments
• sending returns, claims or other documents

Sending returns is on that list, which is why Tomasz is caught even though most of the work is bookkeeping. GOV.UK is clear that the label does not matter. You’ll need to register even if:

• you do not view yourself as a tax adviser, or describe your work as tax advice
• you work as a registered sole trader
• helping people with their tax affairs is not your main business function
• you only interact with HMRC on behalf of one client

It is the business that registers, not each person in it. In GOV.UK’s words:

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

Some people who deal with HMRC for others are outside the requirement. You do not need to register for an agent services account if you only interact with HMRC on behalf of someone else:

• as an employer or part of an in-house tax team (for example, running payroll for your own staff)
• about your own company group’s tax affairs
• to give tax advice for free (for example, through a charity or helping friends or family)
• to develop or provide accounting or tax software (including payroll software)

GOV.UK lists a few more exceptions, mostly for customs work and for representatives, on its page on whether and when you need to register, which also links to HMRC’s own online checker.

When each group registers

HMRC is bringing the requirement in by groups rather than all at once. Its news release calls the new rules Modernising and Mandating Tax Adviser Registration, or MMTAR, and shortens agent services account to ASA. MMTAR registration opened on 18 May 2026 and is being introduced in phases. You’ll have 3 months from the date your registration window opens to apply for an agent services account. The phased rollout timetable is:

If you already have an agent services account, the position is simpler. GOV.UK says: “Tax advisers who already have an ASA do not need to register again. They will be moved to the new digital service by 31 March 2027.” For anyone whose window has passed, GOV.UK’s advice is short. If you missed your registration window, or are new to the market, you should register now.

Waiting for a decision does not stop you working. GOV.UK says:

You can continue to interact with HMRC on behalf of your clients:

• during these 3 months
• while we consider your registration

There is no fee for registering itself. Registration is free and online.

The conditions a practice must meet

Registering means meeting HMRC’s conditions, and the first one comes before the application itself. You must provide evidence that your business is supervised for anti-money laundering, either by HMRC or by one of the supervisory bodies. HMRC adds:

You need to have approved anti-money laundering supervision in place before you apply for an agent services account. If you’ve already applied without being approved, we will reject your application.

Your 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 interact with you
• 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

Certain people in the business are checked as well. Some of the people who work for your business must also meet the conditions. These people are known as ‘relevant individuals’. For a small business, GOV.UK says:

If your business has 5 officers or less, we’ll treat all of them as relevant individuals, even if they’re not all involved in providing tax services.

For a sole trader like Tomasz, that is simply Tomasz. Most of the checking happens without extra paperwork, and it carries on after registration:

In most cases, we’ll check you meet these conditions once you’ve submitted your application online. You will not usually need to provide separate evidence.

We’ll continue to carry out checks to make sure your business still meets the registration conditions, if it does not, your tax adviser registration may be suspended.

What the application asks for

The online application asks for a fixed set of details, so it helps to gather them first. You’ll need:

• your business Government Gateway user ID and password (you can create these on the sign-in page if you do not have them)
• your personal Government Gateway user ID and password (if you are a sole trader)
• the Unique Taxpayer Reference (UTR) for your firm
• the postcode linked to your UTR
• your company registration number (if you have one)
• your VAT registration number (if you have one)
• the name of your anti-money laundering supervisory body, and proof you are supervised
• the names and contact details of relevant people in your business

During the application the service gives you a link for the relevant people in your business. Share this with any relevant individuals in your business so they can sign in and add their details. They must use their own Government Gateway user ID, not the business ID.

Once the account exists, HMRC sets limits on how you describe it. You must not use your agent services account to suggest that:

• HMRC endorses you as a tax adviser
• you are part of HMRC
• you act on behalf of HMRC

HMRC does not endorse individual businesses or tax agents.

If a practice does not register

HMRC describes a gradual approach, starting with help to put things right. HMRC will, where possible, support you to comply before applying a suspension or other sanction. You’ll have a 3-month transition period from the date you need to register. During this time, you will not receive a sanction if you have applied to register but are waiting for HMRC’s decision.

Once that period is over, dealing with HMRC while you should be registered and are not has consequences. If you interact with HMRC whilst you are unregistered or your tax adviser registration is suspended, it will be considered a prohibited interaction and your business or any relevant individuals may get sanctions. GOV.UK sets out the sanctions in this order.

HMRC may also make a sanction public:

If you are issued a financial penalty or a temporary or permanent ban on interacting with HMRC on behalf of clients, we may publish information about you.

A registered practice can still be suspended, either for no longer meeting the conditions or for its conduct. When a condition stops being met, HMRC gets in touch first. You will be given 30 days, from the date of the initial contact, to correct any issues identified. If the issue relates to outstanding or unpaid tax, you will be given 60 days. Tax advisers are expected to comply with HMRC’s standard for agents. If HMRC considers your behaviour to fall below the standard, you may receive a fixed-term suspension. The suspension will come into effect 30 days after receiving the notice of suspension and will last for up to 12 months. Registration is therefore something a practice keeps up over time, rather than a form it fills in once.

Questions about registering as a tax adviser