The Finance Act 2026 (the 2026 Act) has introduced significant new measures requiring tax advisers to register with HMRC. The definition of ‘tax adviser’ for this purpose is very wide, and many law firms who may not regard themselves as providing tax advice could now be required to register.
The window for registration opened on 18th May 2026. Firms that do not currently have an Agent Services Account (ASA) and do not hold Self-Assessment or Corporation Tax agent codes must register by 18 August 2026.
Read the full HMRC guidance here (opens a new window), including how to register for an ASA account.
What are the new rules?
The new provisions stipulate that firms who interact with HMRC on behalf of clients’ tax affairs will be required to register with HMRC as ‘tax advisers’. A firm will be considered a tax adviser for the purpose of the registration requirements even by simply assisting with a document likely to be relied on by HMRC. The changes came into force on 18 May 2026, with a three-month transition period.
Conveyancers are likely to be among the most heavily affected group, including any firms who calculate Stamp Duty Land Tax (SDLT) liabilities, submit SDLT returns, or arrange payment of SDLT on clients’ behalf.
In addition, firms carrying out the following types of work are likely to fall within the registration requirements:
Private wealth and family matters where tax consequences form part of the advice being provided or where HMRC correspondence is required.
Trust-related services, including the ongoing management of trusts and the fulfilment of associated tax obligations.
Business transactions and corporate restructurings that involve the preparation or submission of tax-related information.
Representation of clients in dealings with HMRC, including enquiries, disputes and other contentious matters.
International client work where UK tax reporting, compliance or engagement with HMRC forms part of the retainer.
This list is not exhaustive. As above, any solicitor who communicates with HMRC will be subject to registration requirements.
Do individuals have to register?
The legal entity that interacts with HMRC must register. Individual employees will not need to register separately, but certain ‘relevant individuals’ will need to be named in the registration process (opens a new window). This includes any officers of the business (e.g. directors, partners, members of LLPs) and any other employees who control or significantly influence the firm’s tax work, or perform the activities of a tax adviser.
The number of relevant individuals required will depend on the size of your firm and its number of partners or directors:
Firms with five officers or less – all officers will be treated as relevant individuals, even if they’re not all involved in providing tax services.
Firms with six officers or more – any officers and employees who meet the definition of relevant individuals will be included, but if this is fewer than five, more must be added until at least five are listed.
Firms can choose which officers to include. They do not have to be the most senior or responsible for day-to-day tax advice. More information is available from the Law Society (opens a new window).
What are the risks of non-compliance?
Under the 2026 Act, firms and relevant individuals could be fined for interacting with HMRC without complying with registration requirements. Orders declaring a firm ineligible for registration can also be issued following penalties for multiple breaches.
Suspension or removal from registration could directly impinge on a firm’s ability to carry out instructions for clients. There is also a risk of reputational harm as suspension of registration carries with it a requirement to notify clients.
Practical steps for law firms:
To prepare for the new regime, firms should:
Check the up-to-date guidance from HMRC and establishing whether your firm will need to register.
Identify the ‘relevant individuals’ in your organisation.
Apply for an agent services account and completing the registration process online.
Make diary entries to ensure you meet the deadline for registration.
Firms must remember that registering as a ‘tax adviser’ with HMRC does not mean your firm is qualified to provide tax advice. If you do not provide specialist tax advice, consider whether you are making this clear to clients.
For all firms, it would be sensible to review your letter of engagement to deal with the provision of tax advice. This may include wording which explains your requirement to register with HMRC as a ‘tax adviser’, the meaning of ‘tax adviser’ for the purposes of the regime, and which services you will, and will not, provide in relation to tax.
For more information, reach out to a member of our team.
