HMRC Tax Adviser Registration 2026: What It Means for You and Your Accountant

The UK has, for the first time, a legal requirement for people who deal with HMRC on someone else’s behalf for a living to be registered with HMRC first. It arrived in Chapter 1 of Part 7 of the Finance Act 2026. Registration opened on 18 May 2026; the prohibition on acting unregistered is being switched on in four tranches from 18 August 2026 to 1 April 2027, and it changes what you are entitled to expect from the person who files your return.

This guide is written for the client, not the adviser. If you run a practice, GOV.UK’s checker and conditions page are the operative documents.

What the law actually says

Section 223 of the Finance Act 2026 is the whole rule in one sentence:

A tax adviser may not interact with HMRC in relation to the tax affairs of a client unless (a) the adviser is registered under this Chapter, or (b) an exception in Schedule 20 (exceptions) applies.

“Interact” is defined as widely as it could be. Section 223 lists contacting HMRC “by telephone, post or email”, sending “a message to HMRC through a website or internet portal”, filing “a return, claim, notice or other document with HMRC”, and communicating “with HMRC in any other way”. A “tax adviser” (section 224) is an organisation that, in the course of a business carried on by it, assists other persons with their tax affairs, or an individual who does so in the course of a business carried on as a sole trader.

GOV.UK translates “in the course of a business” into the test that matters for you: “If you interact with HMRC about someone else’s tax affairs and get paid for it, we consider you to be a tax adviser.” The guidance adds that this is so even if the person does not call themselves a tax adviser, works as a registered sole trader, or has a single client.

So the friend who does your return for nothing is outside it. GOV.UK’s list of people who do not need to register includes those who give tax advice for free “for example, through a charity or helping friends or family”, employers and in-house tax teams dealing with their own staff or their own group, VAT representatives, customs specialists, representing a client in appeals to a court or tribunal about business rates, council tax or property valuation (the Act’s Schedule 20 puts it more broadly, as any appeal to a court or tribunal), and software developers. Regulations made in July 2026 (SI 2026/815) added three narrow exceptions to Schedule 20 from 17 August 2026: IOSS representatives acting as such, advisers dealing with a tax not payable to HMRC such as council tax, and property valuations under section 10 of the Commissioners for Revenue and Customs Act 2005.

When it bites: the four tranches

Section 249 left the start date to the Treasury, and SI 2026/807 set it in four tranches. HMRC opened registration on 18 May 2026 and gave each group a three-month application window; the prohibition bites from the tranche date, which for the last group is the day after its window closes. HMRC’s 20 July 2026 announcement and its 18 August 2026 update describe the groups (the July release had listed existing agent services account holders alongside financial services firms in the last window; the August release and the regulations do not); the commencement dates are the regulations’:

Window	Who	Prohibition applies from
18 May to 18 August 2026	New tax advisers, or advisers interacting with HMRC without an agent services account, Self Assessment or Corporation Tax account	18 August 2026
18 August to 18 November 2026	Advisers with a Self Assessment or Corporation Tax account but without an agent services account	18 November 2026
18 November 2026 to 18 February 2027	Advisers who solely provide payroll services	18 February 2027
31 December 2026 to 31 March 2027	Financial services organisations	1 April 2027

A firm that already held an agent services account before 18 August 2026 is not in any window. Regulation 5 of SI 2026/807 treats such an adviser as if they had applied, been approved and been “notified that their registration had effect from 18th August 2026”, and GOV.UK’s guidance says plainly: “If you already have an agent services account, you will not need to register again.” HMRC’s August update adds that those advisers “will be moved to the new digital service by 31 March 2027”. An agent services account is, in GOV.UK’s words, “how tax advisers access HMRC’s online services”, including Making Tax Digital; a firm can file Self Assessment or Corporation Tax through an older agent account without one, which is what the second tranche is for.

The first window, which HMRC says “targeted the smallest agent audience group”, produced “more than 4,000 applications” and “over 2,000 accounts created” according to the same 18 August update.

What registration checks, and what it does not

Registration is not a qualification. HMRC’s own fact sheet puts it bluntly: “Registration is not a form of regulation and does not reflect your competency or authorise you to advise on tax matters.” What it does is let HMRC refuse to deal with advisers who fail a set of objective conditions, set out in section 227 and summarised on GOV.UK’s conditions page, which the list below follows:

• the business is supervised for anti-money laundering and can prove it;
• it has no relevant outstanding tax returns or unpaid tax of its own, “unless covered by a payment plan”;
• HMRC has not already decided to refuse to interact with it;
• it is not subject to an anti-avoidance sanction or a stop notice (the Act adds, at section 227(2)(d), no relevant anti-avoidance penalty in the previous 12 months);
• it has no unspent convictions for fraud or tax offences;
• it is not formally insolvent;
• it is not already suspended or banned from registering.

The same conditions, minus the anti-money laundering evidence, apply to the “relevant individuals” running the firm; not being disqualified as a director applies to the firm and to each of them. Overseas advisers have to supply notarised and, where needed, translated evidence, which GOV.UK says HMRC will ask for rather than expecting it up front.

So a registered adviser is one HMRC has no objective reason to refuse. Whether they are any good at tax is a separate question, answered by professional qualifications, professional-body membership and, frankly, their work.

What happens to an adviser who ignores it

The Act builds a ladder rather than a single cliff. HMRC can monitor the conditions (section 231), suspend a registration where it is no longer satisfied they are met or where the adviser’s conduct “falls below the standards that might reasonably be expected of a tax adviser in their interactions with HMRC” (section 232), issue a compliance notice (section 233), and make ineligibility orders, temporary or permanent (sections 236 and 237). HMRC’s manual is explicit that an interaction before an adviser’s tranche commences cannot be sanctioned as unregistered.

Money comes in at section 234. An adviser with a compliance notice in force who then interacts with HMRC anyway is liable to a penalty of £5,000. It is £10,000 where, in the two years to the contravention, the adviser has already been assessed to a penalty under sections 234 or 235 “on four or more occasions”, or where the adviser is acting under an ineligibility order. HMRC’s 20 July 2026 release puts it in plainer terms: advisers who miss their deadline “may face restrictions on their ability to interact with HMRC on behalf of clients” and “HMRC may apply sanctions including financial penalties”.

The provision written for clients is section 238. An adviser suspended for failing the registration conditions must, if the suspension runs past 30 days, “take reasonable steps to notify each of their clients” within the 30 days that follow; an adviser suspended for conduct, or made ineligible, must do so within 30 days of the suspension or order taking effect. The penalty for not doing so is £5,000 “in respect of each client”. If your adviser goes quiet and HMRC starts writing to you directly, that section is why you should have heard from them first.

What to ask your accountant

Four questions cover it:

1. Do you have an agent services account, and if not, which tranche are you in? A firm with one before 18 August 2026 is treated as registered. A sole practitioner filing through an older Self Assessment agent login has until 18 November 2026 to apply; a payroll bureau until 18 February 2027.
2. Who supervises you for anti-money laundering? For accountants this is usually a professional body such as the ICAEW, ACCA or CIOT, or HMRC itself for accountancy service providers no body supervises. It is the one registration condition that needs documentary evidence, so a firm that cannot answer is a firm that cannot register.
3. Are your own tax affairs up to date? An odd question to ask, but an adviser with returns outstanding or tax unpaid outside a payment plan fails the conditions.
4. Will you tell me if HMRC suspends you? They are obliged to. Asking makes clear you know that.

There is, as at September 2026, no public list for you to check against. The nearest thing in the Act is section 246, which lets HMRC publish details of advisers it has penalised or made ineligible; HMRC’s manual calls it the power to publish details of sanctioned tax advisers. It names the bad, not the registered. Until something else appears, the answer to “are you registered” has to come from the adviser.

Why it was introduced

The policy paper of 26 November 2025 traces the measure to a consultation in October 2024 on raising standards in the tax advice market, where respondents “strongly supported mandatory registration” as a way to “enhance the security of tax adviser services and deter unscrupulous actors”. The government put £36 million into modernising HMRC’s agent registration systems to carry it. The stated objective is narrow and worth holding HMRC to: to improve its “ability to monitor and exclude tax advisers who are objectively unable to meet HMRC’s Standards for Agents or cannot lawfully act as a tax adviser”. It is a floor, not a badge.

Related reading

• Personal tax account guide - what you can see and do yourself, adviser or not.
• Payslip fraud: how to check - a different kind of check on who is handling your money.
• Self Assessment 2026/27 - the return most advisers are registered to file.