Conveyancers and HMRC’s 2026 Registration Rules: The SDLT Compliance Risk

From 18 May 2026, a new HMRC registration requirement comes into force for anyone interacting with them on behalf of clients in relation to tax. 

At first glance, many firms will assume this sits firmly with their tax teams. In practice, the scope is much wider, and for conveyancers in particular, it’s easy to underestimate how directly this applies. 

HMRC’s definition of a “tax adviser” under the new regime is deliberately broad. It goes beyond those who formally present themselves as specialists. 

If your firm submits Stamp Duty returns, corresponds with HMRC for a client, or handles any part of a client’s tax interaction, you are likely within scope. That includes work arising as part of conveyancing or private client matters. 

The Law Society has already highlighted that many conveyancers may not yet recognise their exposure. That’s a point worth pausing on. 

Conveyancing may not feel like tax advice, but for HMRC, submitting a return on behalf of a client is enough to trigger the requirement. The threshold is low. The obligation that follows is not. 

“For firms already operating with robust procedures and clear documentation, the administrative burden should be manageable. The greater risk lies in lack of awareness.” 

Huzaifah Malik, Head of Stamp Taxes, Bonham & Brook

What the regime requires in practice 

Firms with an existing Agent Services Account are not required to re-register immediately, although HMRC may seek further information to confirm that existing arrangements remain compliant. For others, a staged registration window applies with a three-month period to complete the process.  

The deadlines are firm, and the risk of missing them is not only a penalty in the conventional sense, but the inability to act for clients before HMRC at all. 

That operational consequence is what distinguishes this reform from much of the compliance landscape. It is not primarily a financial risk, it is a practice risk; one that if realised would affect a firm’s ability to serve clients in a fundamental way. 

In the broader context 

It would be a mistake to view this as a standalone change. It forms part of a wider shift by HMRC to tighten oversight of who engages with them, particularly in areas involving professional judgement, such as SDLT. 

Expectations around evidence and documentation have been increasing for some time. This regime formalises a standard that was previously implied. 

For firms already operating with clear processes and well-documented files, the transition should be straightforward. For others, this may prompt a broader review of how Stamp positions are formed, evidenced, and recorded. 

There are also practical considerations around how this interacts with existing regulatory frameworks, including the SRA. For smaller firms, especially, the overlap in obligations and the resources required shouldn’t be underestimated. 

Practical Next Steps for Firms 

• Confirm whether your firm falls within scope (Stamp return submissions alone may be enough) 
• Review your Agent Services Account status and whether further information may be required 
• Assess how SDLT positions are evidenced and documented across the team 
• Consider how this aligns with existing SRA obligations, particularly for smaller practices 
• Allow sufficient time to complete registration ahead of 18 May 

Awareness 

This reform is ultimately less about process than it is about establishing a defined standard for how firms engage with HMRC from now on.  

For firms that already operate with discipline and structure, the principal task is ensuring registration is completed in time. For those who have not yet engaged with the question, the more pressing task is understanding whether it applies to them at all. 

Lack of awareness, at this stage, remains the major risk. The regime will not make allowances for firms that were unaware of their obligations. Acting now to confirm scope, check existing arrangements and register where required can ensure you remain in a position to support your clients without disruption.

What this means for your property transactions 

The new regime, which falls under the Finance Bill 2026, may include Stamp Duty Land Tax (SDLT) submissions. Any professional who is responsible for submitting those returns as part of a property transaction will be caught by the new requirements. 

This means anyone who is not registered will be unable to interact with HMRC, which could slow your transaction down, whether you are buying your first home or adding to your portfolio. 

Your professional team should have contacted you to let you know that they are registering and any delays that may happen if they haven’t. It’s a good idea to be proactive and reach out to them yourself.  

The impact on Professional Indemnity Insurance 

Each claim will be treated on its own individual merit, and insurers would expect firms to remain up to date and compliant with any changes in legislation.

They would investigate to deem the negligence involved (whether it may have been deliberate or otherwise) and proceed accordingly.

Failure to remain compliant could result in a policy lapse. It is always worth contacting your professional indemnity provider to understand how this regime will affect your policy. 

How Karis Capital can help

As compliance rules continue to change, so do the responsibilities of the firms involved in property transactions. Planning your transaction from the beginning is becoming crucial for property investors and developers. 

Whether purchasing a first home or expanding an existing property portfolio, Karis Capital and Karis Insurance can support clients to navigate and plan for these changes. 

Ensuring that even as compliance requirements evolve, clients remain financially resilient and well-positioned to achieve their business goals. Get in touch with our team here.