Guidelines for SDLT Agent Authorisation and Repayment Procedures with Letter Templates

When HMRC Will Speak to an SDLT Agent

HMRC will usually only deal with the agent named on the original SDLT return. If a different adviser wants to act, or if a repayment is to be sent to that adviser, HMRC normally needs a signed letter of authority from the purchaser before it will discuss the case or process the refund.

• The agent named on the SDLT return is normally treated as the authorised agent for that matter.
• If a new agent, replacement conveyancer or claims firm takes over, HMRC will usually require a written letter of authority signed by the purchaser.
• Where there is more than one purchaser, every purchaser must sign the authority.
• A separate point applies to refunds: HMRC needs clear written consent if the repayment is to be paid to the agent instead of the purchaser.
• HMRC says it must receive the authority before it will process a repayment to the agent, so missing paperwork can cause delay.

Scroll down for the full analysis.

When HMRC will speak to an SDLT agent: letters of authority explained

This page explains when HMRC will deal with someone acting for a purchaser on Stamp Duty Land Tax matters, and when a separate letter of authority is needed. The point matters because HMRC may refuse to discuss a case or delay a repayment if the right authority is not in place.

What this rule is about

In SDLT cases, HMRC will usually treat the agent named on the SDLT return as the person authorised to deal with the matter. If someone else later wants to act, HMRC requires clear written authority from the purchaser.

The same issue arises with repayments. If an agent asks HMRC to send an SDLT refund to the agent rather than to the purchaser, HMRC requires specific written authority confirming that the purchaser agrees.

This is essentially an authorisation rule. It is about who HMRC is allowed to speak to and who HMRC is allowed to pay.

What the official source says

The HMRC manual says that SDLT matters cannot be discussed with an agent other than the one listed in the SDLT return unless HMRC has received a letter of authority. That letter must authorise the different agent to act and must be signed by the purchaser. If there is more than one purchaser, each purchaser must sign.

The manual also says that a letter of authority is required where an agent asks for an SDLT repayment on behalf of the purchaser and wants the repayment to be made to the agent. The letter must confirm that the purchaser, or each joint purchaser, is content for the repayment to be sent directly to that agent. HMRC must receive that authority before the repayment is processed.

The manual refers to an HMRC template letter of authority.

What this means in practice

If the SDLT return named one firm or one individual as agent, HMRC will normally only discuss the case with that named agent. A new adviser, replacement conveyancer, tax agent, or claims company cannot simply contact HMRC and expect to deal with the matter straight away.

Instead, HMRC will want a signed letter of authority from the purchaser. In a joint purchase, that means authority from every purchaser, not just one of them.

This becomes especially important where there is a refund claim. Even if an agent is acting for the purchaser, HMRC will still require a signed authority before sending the money to the agent rather than to the purchaser directly.

So there are really two separate questions:

• Who is authorised to discuss the SDLT matter with HMRC?
• If there is a repayment, who is authorised to receive it?

The answer to the second question needs to be explicit. HMRC wants confirmation that the purchaser agrees to the repayment being paid to the agent.

How to analyse it

When dealing with an SDLT enquiry, amendment, or refund request, it helps to work through the following points.

• Check who is named as agent on the original SDLT return.
• If a different person or firm is now acting, ask whether HMRC has already received a signed letter of authority.
• If there is more than one purchaser, check whether every purchaser has signed the authority.
• If a repayment is being claimed, ask whether the purchaser wants the money paid to them or to the agent.
• If the repayment is to go to the agent, make sure the authority clearly says that the purchaser agrees to this.
• Do not assume HMRC will process the repayment first and sort out authority later. The manual says the authority must be received before the repayment is processed.

In practice, this means conveyancers and tax advisers should deal with authority early, especially if the original filing agent is no longer involved.

Example

A and B bought a property jointly and their conveyancer filed the SDLT return. Later, a tax adviser reviews the transaction and believes too much SDLT was paid. The adviser contacts HMRC to discuss the case and asks for any repayment to be sent to the adviser’s client account.

On the HMRC approach described in the manual, that adviser cannot simply step in because they were not the agent named on the SDLT return. HMRC will require a letter of authority signed by both A and B authorising the adviser to act. If the repayment is to be sent to the adviser rather than to A and B, the letter must also confirm that both purchasers agree to that payment arrangement. HMRC must receive that before processing the refund.

Why this can be difficult in practice

The rule is simple in principle, but a few practical issues often arise.

First, joint purchases can create delay. The manual requires the letter to be signed by each purchaser, so authority from only one co-purchaser is not enough.

Second, readers may assume that a general engagement letter with an adviser is enough. The manual does not say that any private retainer between client and adviser will satisfy HMRC. What it refers to is a letter of authority received by HMRC and signed by the purchaser or purchasers.

Third, the authority to discuss a case and the authority to receive repayment funds should not be blurred together. If an agent wants the money paid to them, HMRC expects that to be expressly confirmed.

Finally, the source is an HMRC manual page, so it describes HMRC’s administrative practice rather than setting out a full statutory code on agency. In practice, however, this is the approach taxpayers and agents will usually need to satisfy when dealing with HMRC on SDLT processing matters.

Key takeaways

• HMRC will normally only discuss an SDLT case with the agent named on the SDLT return unless a signed letter of authority is provided for a different agent.
• For joint purchases, each purchaser must sign the letter of authority.
• If an agent wants an SDLT repayment paid to them, HMRC requires written confirmation from the purchaser or purchasers before processing the repayment.

This page was last updated on 24 March 2026

Useful article? You may find it helpful to read the original guidance here: Guidelines for SDLT Agent Authorisation and Repayment Procedures with Letter Templates

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