The HMRC standard for agents

The HMRC standard for agents sets out the behaviour HMRC expects from anyone who deals with it professionally on someone else’s tax affairs, whether or not they belong to a professional body. Since 2026 it has teeth: registered tax advisers must act consistently with it to stay registered, a serious breach can lead to suspension for up to 12 months, and deliberate wrongdoing now falls under a tougher sanctionable conduct regime.

What is the standard and who does it apply to?

HMRC first published the standard in February 2016 and updated it in 2018 and 2023; the current version was last updated on 9 February 2026. It says what HMRC expects of tax agents and advisers in their dealings with HMRC and how HMRC will tackle the minority who fall short. It does not replace the law or HMRC guidance, and it does not override legal professional privilege or professional body duties.

The standard applies to all individuals and businesses acting professionally in relation to the tax affairs of others, in the UK or abroad. HMRC’s list expressly includes accountants and bookkeepers, agents who only file returns, agents who act for clients without giving tax advice, lawyers and other professionals advising on tax alongside other work, and agents who help clients claim repayments or reliefs. It does not apply to trusted helpers such as family members.

How does it relate to professional body rules?

HMRC estimates that around 65% of agents are members of professional bodies. The largest accountancy and tax bodies apply their codes of ethics to tax work through Professional Conduct in Relation to Taxation (PCRT), which HMRC recognises and endorses. The standard focuses on three of PCRT’s five fundamental principles: integrity, professional competence and due care, and professional behaviour. Objectivity and confidentiality are not specifically covered.

HMRC expects every agent to keep to its standard regardless of membership, but says that an agent who meets their professional body’s code of ethics should not face further requirements from it. For unqualified and unaffiliated agents, the standard is in practice the main written statement of the conduct HMRC expects.

What does HMRC expect in practice?

Section 4 of the standard is short and specific. The main expectations are these.

Integrity

• Tell HMRC if relevant information cannot be given because the client has not given permission.
• Respond promptly when HMRC uses its information powers.
• Never suggest that HMRC endorses the agent or that the agent is part of HMRC, and make the legal identity of a business clear where it trades under another name.

Professional competence and due care

• Keep knowledge up to date in the taxes the agent deals with.
• Avoid unsubstantiated or speculative figures in returns and claims.
• Keep contemporaneous records of what was advised and when.
• Advise clients to correct errors; if a client refuses, consider ceasing to act, because continuing could risk enabling evasion.
• Keep client information secure and check that software and third party input give accurate results.

Professional behaviour

• Keep the agent’s own tax affairs correct and up to date, including any Time to Pay arrangement.
• Register for and follow the Money Laundering Regulations 2017, submit Suspicious Activity Reports, and comply with data protection, consumer and advertising law.
• Work constructively with HMRC in enquiries, comply with HMRC’s online services terms, and only access client data through the agent services account after proper authorisation.
• Never ask a client to share their HMRC sign in details.
• Agree clear terms of engagement before acting, covering fees, how repayments will reach the client and any deductions, and the right to end the arrangement.
• Pass documents and information to a client’s new adviser where the client is entitled to them, unless there is a legal reason not to.

On tax planning, the standard says agents must not create, encourage or promote arrangements that set out to achieve results contrary to the clear intention of Parliament, or that are highly artificial or contrived and exploit shortcomings in the legislation. Advice should rest on a realistic view of the facts and a credible view of the law, flag material uncertainty and explain the risk and cost of challenge.

Why does the standard carry more weight since 2026?

Under mandatory registration, set out in our page on mandatory registration of tax advisers, a registered business and its relevant individuals must act consistently with the standard when dealing with HMRC in order to remain registered (MTAR20200). HMRC may suspend a registered tax adviser whose behaviour falls below the standards reasonably expected of an adviser (section 232 Finance Act 2026, explained at MTAR30200).

This type of suspension is fixed term, for up to 12 months, and cannot be extended. HMRC must give notice and allow, in most cases, 30 days for representations before it takes effect. Ministers told the Finance Bill committee that a serious breach would result in suspension but a minor breach would not, and that HMRC would not suspend where it would be unreasonable or disproportionate. While suspended, the firm loses its agent services account and cannot deal with HMRC for clients by any channel, and it must notify its clients within 30 days of the suspension taking effect (MTAR30550). Failing to tell a client can cost £5,000 per client.

What if a suspended firm keeps dealing with HMRC?

HMRC’s guidance sets out an escalating ladder. The first prohibited interaction brings a formal compliance notice. Each later interaction while the notice is in force carries a £5,000 penalty. A fifth penalty within two years of the first is £10,000 and triggers a 12 month temporary ban; an interaction during that ban brings a permanent ban, and every further interaction costs £10,000. HMRC may publish the names of those penalised or banned.

What powers does HMRC have over deliberate wrongdoing?

From 1 April 2026 the Finance Act 2026 replaced the old dishonest conduct regime in Schedule 38 to the Finance Act 2012 with a “sanctionable conduct” regime. Sanctionable conduct is doing something, in the course of acting as a tax adviser, with the intention of bringing about a loss of tax revenue, whether or not a loss results and whether or not the client gave instructions. HMRC’s examples include knowingly claiming a repayment a client is not entitled to or submitting an incorrect return. Honest mistakes are not included.

Where it suspects sanctionable conduct HMRC can issue a file access notice for working papers. A deliberate or careless inaccuracy in papers supplied can cost up to £3,000 for each inaccuracy; failing to supply them brings a £300 penalty and daily penalties of up to £60. If HMRC decides the conduct occurred it issues a conduct notice and a penalty based on potential lost revenue:

Number of penalties	Percentage of potential lost revenue	Maximum penalty
1	up to 70%	£1 million
2 to 5	up to 85%	£5 million
6 or more	up to 100%	No maximum

The minimum penalty is £7,500, and HMRC must publish the details of anyone charged more than £7,500. Disclosure reduces the percentage: under paragraph 26 of Schedule 38 it cannot fall below 35% for a prompted disclosure or 20% for an unprompted one.

HMRC also lists other responses to poor standards: blocking access to agent services, refusing to deal with an agent altogether, criminal investigation, and telling the agent’s professional body through a public interest disclosure. Section 251 of the Finance Act 2026 lets HMRC publish an adviser’s details where it has refused to deal with them or suspended their online access and publication is in the public interest, after giving at least 30 days to make representations.

Illustration only. A practice discovers that a client’s last two returns omitted rental income. The standard expects it to advise the client to disclose. The client refuses. If the practice simply files the next return without the income, it moves from an innocent error towards knowingly submitting an incorrect return, which is the territory of sanctionable conduct. The safer course is to record its advice, consider ceasing to act, and consider its reporting duties under the Proceeds of Crime Act 2002.

What mistakes put agents in breach?

• Asking clients for their HMRC or One Login credentials to “save time”.
• Letting the firm’s own returns or a Time to Pay arrangement slip.
• Advertising in a way that implies an official link with HMRC.
• Including estimated or unsupported figures without saying so; see estimated figures on a tax return.
• Starting work without agreed terms of engagement; see engagement letters for accountants.
• Ignoring HMRC information requests or failing to hand over records to a new adviser.

Solar Protect runs fee protection schemes for accountancy and bookkeeping practices. See how our accountant schemes work or read fee protection schemes for accountants.

Related Accountapedia entries

• PCRT: the standards for tax planning
• Can HMRC penalise an agent for a client’s errors
• Regulated vs unregulated accountants
• HMRC powers over dishonest tax agents
• When a client will not correct a tax error

Sources

• GOV.UK: The hmrc standard for agents
• GOV.UK: Hmrc the standard for agents
• GOV.UK: Manual page MTAR20200
• GOV.UK: Manual page MTAR30200
• GOV.UK: Manual page MTAR30100
• GOV.UK: Manual page MTAR30550
• GOV.UK: What happens if you interact with hmrc when you are unregistered or su
• GOV.UK: How hmrc deals with tax adviser sanctionable conduct
• legislation.gov.uk: Act 2012 c. 14, schedule 38
• legislation.gov.uk: Act 2012 c. 14, schedule 38

Reviewed by Christine Anderson, Broker, Solar Protect. Last reviewed 8 October 2026. Part of Accountapedia, the Solar Protect guide to UK tax and accounting. This page is general information, not personalised advice.