Key takeaways

  • The HMRC Standard for Agents applies to every individual and business acting as a tax agent or adviser, whether or not they belong to a professional body.
  • The standard has four parts: integrity, professional competence and due care, professional behaviour, and tax planning.
  • Agents must never ask a client for their HMRC online sign-in details and must keep their own tax affairs up to date.
  • Agents must not create, encourage or promote tax arrangements that are highly artificial or contrived or that go against the clear intention of Parliament.
  • HMRC can respond to breaches by blocking access to agent services, issuing dishonest conduct notices, opening a criminal investigation or refusing to deal with the agent.
  • Members of professional bodies who follow their body's code and PCRT, whose current edition took effect on 1 January 2026, should not face extra requirements.

HMRC’s Standard for Agents sets out what HMRC expects of everyone who acts as a tax agent or adviser. It covers integrity, professional competence, professional behaviour and tax planning, and applies whether or not you belong to a professional body. With mandatory tax adviser registration now in force and the second window closing on 18 November 2026, HMRC has a direct way to exclude advisers who fall short.

Who does the standard apply to?

The standard applies to every individual and business acting as a tax agent or adviser. HMRC’s Standard for Agents, last updated on 9 February 2026, lists:

  • accountants, bookkeepers and filing-only agents
  • third-party agents, including those helping with repayment or relief claims
  • lawyers and other professionals who give tax advice
  • UK-based and overseas agents dealing with UK tax

It covers all your dealings with HMRC. It does not apply to trusted helpers.

How does it relate to PCRT and your professional body?

If you follow your professional body’s code and Professional Conduct in Relation to Taxation (PCRT), the HMRC standard should not add further requirements. HMRC says around 65% of agents belong to a professional body.

PCRT is prepared jointly by seven accountancy and tax bodies, including ICAEW and the ATT. The ATT says its current edition took effect on 1 January 2026 and aligns with the IESBA tax planning provisions. The HMRC standard picks out three of PCRT’s five fundamental principles: integrity, professional competence and due care, and professional behaviour.

Agents who are not members of a professional body must still meet the standard in full.

What the standard requires

The standard has four parts in section 4.

SectionCovers
4.1 IntegrityHonesty, prompt responses, clear identity
4.2 Competence and due careKnowledge, accuracy, records, security
4.3 Professional behaviourLaw, HMRC dealings, clients
4.4 Tax planningLawful advice, no contrived schemes

Integrity (4.1)

You must be straightforward and honest with HMRC. You should respond promptly to HMRC information powers, tell HMRC when you cannot provide information because the client has not given permission, and make your identity and any trading name clear. You must not suggest HMRC endorses you.

Professional competence and due care (4.2)

You must keep your tax knowledge up to date and take care to avoid errors. That means:

  • no speculative or unsubstantiated figures in returns or claims
  • contemporary records of the advice you gave and when
  • advising clients to correct errors, and considering ceasing to act if they refuse
  • keeping client information secure
  • checking that software and specialist inputs are accurate

Professional behaviour (4.3)

Your firm must keep its own tax affairs correct and up to date, including any Time to Pay arrangement. You must comply with the Money Laundering Regulations 2017, UK GDPR and the Data Protection Act 2018, and submit Suspicious Activity Reports to the National Crime Agency under the Proceeds of Crime Act 2002.

With HMRC, you should work constructively and keep your online credentials safe. You should access client data only with authorisation, through the agent services account.

With clients, the standard sets two hard rules and several expectations.

  • Must: never ask a client for their HMRC online sign-in details or digital certificate.
  • Must: make communications and advertising fair, clear, accurate and not misleading.
  • Should: agree clear terms of engagement before acting, covering fees, how repayments reach the client, deductions and how to end the arrangement.
  • Should: offer a reasonable cancellation period and hand over documents to a new adviser when the client is entitled to them.

Our guide to engagement letters for accountants covers the terms side.

Tax planning (4.4)

Tax planning must be lawful and based on realistic facts and a credible view of the law. You must explain material legal uncertainty and the risks and costs of a challenge. You must not create, encourage or promote arrangements that are highly artificial or contrived, exploit shortcomings in legislation, or go against the clear intention of Parliament. Keep notes of your reasoning.

For the wider crackdown, see the ban on promoting tax avoidance.

What happens if you breach the standard?

HMRC looks at each case individually and usually works with the agent first. If the agent does not engage, or the breach is serious, HMRC can:

  1. block access to HMRC’s agent online services
  2. issue a dishonest tax agent conduct notice, with possible penalties and publication
  3. open a criminal investigation if it suspects an offence
  4. refuse to deal with the agent

HMRC can also tell your professional body through a public interest disclosure.

Registration gives HMRC a gatekeeping tool. Its policy paper on mandatory registration says the aim is to monitor and exclude advisers who cannot meet the Standard for Agents. Registered advisers must give annual assurances that they still meet the registration conditions, including approved AML supervision and no unpaid tax or unfiled returns.

The policy paper does not say exactly how a breach of the standard leads to suspension.

What your firm should do now

  1. Register by 18 November 2026 if you are in the second window. See the tax adviser registration deadline.
  2. Check the firm’s own tax affairs, and those of each relevant individual.
  3. Review engagement letters against section 4.3.3.
  4. Stop any practice of holding client sign-in details.
  5. Record CPD to show your knowledge is current. See CPD requirements for accountants.
  6. Keep advice notes with dates, especially for any tax planning.

Frequently asked questions

What is the HMRC Standard for Agents?

It is HMRC’s statement of the standards it expects from all tax agents and advisers. It covers integrity, competence, professional behaviour and tax planning.

Does the standard apply if I am not a member of a professional body?

Yes. It applies to all agents, whether or not they belong to a professional body.

Can I ask a client for their HMRC login to file their return?

No. The standard says agents must never ask clients to share their HMRC online services sign-in details or digital certificate.

What can HMRC do if an agent breaches the standard?

HMRC can block access to agent services, issue a dishonest tax agent conduct notice, open a criminal investigation or refuse to deal with the agent.

When was the Standard for Agents last updated?

HMRC’s page was last updated on 9 February 2026. The standard was first published in 2016 and updated in 2018 and 2023.

Sources

Rates, thresholds and rules in this guide were checked against HMRC and GOV.UK guidance on 6 November 2026. Tax rules change, so check the current position on GOV.UK or with a qualified adviser before acting. This guide is general information, not personal advice.