Does your law firm need to register as a tax adviser with HMRC?

If your law firm interacts with HMRC about someone else’s tax affairs then you may be affected by the changes coming in on 18 May 2026.

From this date, HMRC require all tax advisers to register for an agent services account. You may not consider your firm to be a tax adviser, however, if you submit returns, including stamp duty land tax returns, to HMRC for your client then you are captured by these changes. Both the Law Society and The Council for Licensed Conveyancers have urged the treasury to rethink this requirement, as it is felt to create unnecessary regulatory burdens. However, HMRC guidance is still unchanged. HMRC have confirmed that filing tax returns, including stamp duty land tax returns, for a taxpayer is defined as tax advice. This is because HMRC will use this information to determine how much tax is due. As a result, conveyancers who interact with HMRC on behalf of their clients will be required to register.

Which law firms need to register

The law firm is required to register but you will also need to consider if any people in your firm are considered to be ‘relevant individuals’. At the time of registering the firm you will need to provide details about these relevant individuals. You need to consider the number of officers (partners, members or directors) in your firm to help determine who the relevant individuals are:

• If five or fewer officers – all will be treated as relevant individuals, even if they are not involved in providing tax services
• If six or more officers – only officers involved in tax adviser activities and those who play a significant role in managing or organising these activities are relevant individuals. If this comes to less than five people then further officers are to be nominated to take the total of relevant individuals up to five

Registration conditions for law firms

There are certain conditions that your firm and the relevant individuals need to meet to ensure that HMRC will accept your registration as a tax adviser.

The main condition is providing evidence that your firm is supervised for anti-money laundering. You will not need to specifically register with HMRC under the anti-money laundering regulations providing you are already supervised by another professional body, likely the SRA. HMRC will need evidence of this.

Your firm must also 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 deal 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

The same conditions will apply to the relevant individuals other than:

• Individuals will not need to provide evidence of anti-money laundering supervision
• Individuals must not be disqualified from acting as a director

It currently appears that HMRC will check if the firm and individuals meet these conditions when you apply. You will not need to supply separate evidence directly to them unless specifically requested.

When law firms to register

The HMRC guidance currently states that you can register for an agent services account from 18 May 2026. Please note you are unable to start this process before this date. There is currently no guidance available on how the registration process will work. This is to be updated nearer the registration date. HMRC are stating that you will have three months to register with a deadline of 18 August 2026. You are able to interact with HMRC on behalf of your clients during this time.

If your firm already has an agent services account with HMRC for another reason, you will not need to register with them again. HMRC will contact you through your agent services account when they need more information.

A Law Society Gazette article published on Thursday 19 March noted that a government statement confirmed that ‘the registration of businesses in the financial services sector will be deferred until 31 March 2027 to allow time to get this right’. They were indicating that there could be a delay to the registration deadline for other entities including law firms. However, there is nothing official stating this to be the case currently.

Implications of law firms not registering

If you are required to register but do not by the required deadline you will not be permitted to interact with HMRC. Therefore, if you provide conveyancing services you will be unable to file stamp duty land tax returns on behalf of your client. This will slow down the process and undoubtedly result in disappointed clients. HMRC have also indicated that they may either issue a formal notice asking you to stop interacting with them. This could mean you are unable to file further returns, or are temporarily or permanently banned from being able to register with HMRC. This would cause significant long term issues for your firm.

If you believe your firm will be caught by these new requirements keep an eye on the Gov website for further details on how to register. This will help ensure you meet the required deadline and avoid any negative implications for your firm or clients.