Outsourcing SDLT is becoming more common in 2026, but not all models are the same.
Firms are often presented with a range of options, from simple calculation tools to more involved support services. On the surface, they can appear similar. In practice, the differences are significant.
Before making a decision, it is worth being clear on what actually matters.
The first question is who is acting as the tax agent.
This is fundamental. The submitting agent is the party recorded on the SDLT return and the one holding authority to file. If the firm remains the submitting agent, then the firm remains central to the process, regardless of what support is being used.
The second question is who is responsible for the calculation.
If the firm is still reviewing, approving, or signing off the SDLT position, then responsibility has not truly moved. The distinction between assistance and ownership becomes important here.
The third question is what happens if HMRC opens an enquiry.
It is one thing to prepare a return. It is another to defend it. Firms should be clear on who manages correspondence, who justifies the position taken, and how that process works in practice.
The fourth question is how the process is evidenced.
A robust SDLT model should provide a full audit trail. That includes client confirmations, factual inputs, calculation rationale, and a clear record of submission. Without that, it can be difficult to demonstrate how a position was reached if it is ever reviewed.
The fifth question is where the financial risk sits.
If a calculation is wrong, who carries the consequence? Is there a defined liability position, and is it supported by appropriate professional indemnity cover? These are not theoretical questions. They only become visible when something goes wrong.
This is where Concierge differs from partial or supported models.
Concierge is structured so that it is the named submitting tax agent, with authority obtained directly from the purchaser. The SDLT calculation is carried out within that framework, and the position is documented as part of a complete audit trail.
If HMRC raises questions, Concierge manages the correspondence and supports the position taken. Where an issue arises from the calculation, it is backed within a defined liability framework, supported by professional indemnity cover of £2,000,000 per claim without an annual aggregate limit.
The result is not just that SDLT is outsourced, it is that responsibility, process, and risk are clearly defined. That is the difference firms should be looking for.
To find out more about Compass Concierge book a no obligation meeting here.