Property firms handling Stamp Duty Land Tax submissions will need to register as tax advisers under new HMRC rules coming into force in May 2026. The guidance clarifies requirements for conveyancers and other professionals acting on behalf of landlords and property investors.
Registration now mandatory
HMRC has published guidance outlining that any business paid to deal with tax matters on behalf of clients must register through HMRC’s Agent Services Account. The rules apply to firms submitting returns, claims, or other documents – and to those communicating with HMRC via phone, post, email, or online systems.
For landlords completing property purchases, the change affects how conveyancers handle SDLT submissions and may prompt some firms to review their compliance processes ahead of the deadline.
Conveyancers reclassified as tax advisers
Sean Swimby, director at SCA Tax, said the guidance represents a significant shift. “This guidance is the formal confirmation of what the industry has been anticipating. HMRC has now clearly defined that if you are paid to interact with HMRC in relation to tax, you are acting as a tax adviser and must meet their conditions and register accordingly,” Swimby said.
“For many firms involved in SDLT submissions, this represents a fundamental change in how their role is viewed from a regulatory and compliance perspective. SDLT has often been treated as an administrative step within the conveyancing process, but HMRC’s position makes clear that it falls within the scope of tax advice when firms are acting on behalf of clients.”
Firms must meet new standards
The change requires firms to meet the standards, processes and oversight expected of registered tax advisers. For landlords, this may mean additional due diligence when selecting conveyancers for property transactions, particularly for complex SDLT calculations involving multiple properties or reliefs.
SCA Tax, which has worked with more than 7,000 clients and completed over 20,000 SDLT assessments, said the publication of formal guidance provides clarity ahead of the May 2026 implementation deadline.
The changes form part of HMRC’s broader focus on standards, accountability, and oversight in the tax advice sector. Further details are available on the HMRC website.
Swimby added: “This is ultimately about ensuring appropriate oversight and professional standards when dealing with tax. Firms that interact with HMRC on behalf of clients will need to consider how they meet these requirements going forward.”
Editor’s view
Landlords should ask their conveyancer whether they’re registered as a tax adviser. If they’re handling your SDLT submission, they should be. This is HMRC tightening up – and firms that fail to register could face problems that end up delaying your transaction.
Author: Editorial Team – UK landlord & buy-to-let news, policy, and finance
Published: 18 February 2026
Sources: HMRC, SCA Tax
Related reading: Stamp duty errors costing landlords thousands in missed SDLT refunds
