Guidelines for Deferring Tax Payment on Contingent or Uncertain Land Transactions

SDLT deferral for contingent or uncertain consideration

Where part of the price for land is not fixed when a transaction completes, HMRC may allow Stamp Duty Land Tax to be deferred. If HMRC accepts a deferral application, its notice must clearly state the agreed terms, the SDLT due with the original return, the future dates or events that matter, and how any later tax will be calculated. The approval only remains effective if the application was accurate and complete and the relevant facts do not later change.

• HMRC’s acceptance notice must set out the terms of the deferral and the amount of SDLT payable immediately with the first land transaction return.
• The notice must identify the future event or date that will trigger any further SDLT becoming due.
• It must also explain how the later SDLT is to be calculated when that event happens or the date is reached.
• If the application contained false information or failed to disclose relevant facts, HMRC’s acceptance is treated as having no effect.
• If the facts or circumstances later change, for example because the deal is varied, the deferral approval may stop applying and should be reviewed.

Scroll down for the full analysis.

SDLT deferral for contingent or uncertain consideration: what HMRC’s acceptance notice must cover

This page explains what happens if HMRC agrees to defer payment of Stamp Duty Land Tax because part of the consideration is contingent or uncertain. The point is procedural, but it matters because HMRC’s acceptance notice sets the framework for when tax becomes payable later and how it will be worked out. It also matters because an approval can stop having effect if the application was inaccurate, incomplete, or later overtaken by events.

What this rule is about

In some land transactions, the amount payable for the property is not fully fixed at the effective date of the transaction. Part of the consideration may depend on a future event, or the amount may simply not yet be known. Finance Act 2003 allows, in some cases, payment of SDLT to be deferred rather than paid immediately on an amount that cannot yet be finalised.

The material here is about what HMRC must say when it accepts an application for deferral, and when that acceptance can later become ineffective.

What the official source says

According to the HMRC manual, if an application to defer payment is approved, HMRC’s notice of acceptance must do four things:

• set out the terms on which the application is accepted;
• specify the amount of tax payable with the initial land transaction return;
• identify the dates of the relevant future events; and
• explain how the tax is to be calculated on those dates.

The source also says that an accepted application has no effect if it contains false information, or if relevant facts or circumstances were not disclosed to HMRC.

It further says that the application will cease to have effect if the relevant facts and circumstances later change.

What this means in practice

An approval to defer SDLT is not a blank cheque to sort things out later. HMRC’s acceptance notice should tell you exactly what has been agreed and how the deferred part will operate.

In practice, the notice should enable the taxpayer and their adviser to answer these questions:

• How much SDLT must be paid now with the original return?
• What future event or date will trigger further tax becoming due?
• How will that later tax be calculated?
• What assumptions is HMRC accepting for the purpose of the deferral?

This matters for compliance. If the transaction later reaches one of the relevant dates or events, the taxpayer will need to calculate and pay the further SDLT in the way described in the acceptance notice.

It also matters for risk. HMRC’s acceptance is only effective on the basis of the facts put before it. If the application included false information, or left out something relevant, the acceptance is treated as having no effect. If the facts later change, the acceptance ceases to have effect from that point.

How to analyse it

When reviewing an SDLT deferral approval, it helps to work through the following points.

• Identify the contingent or uncertain element. What part of the consideration was not fixed when the return was filed?
• Check what HMRC accepted. Read the notice carefully. The legal and practical position depends on the terms of acceptance, not just on the fact that HMRC said yes.
• Confirm the immediate SDLT liability. The notice should state how much tax is payable with the initial return.
• Identify the trigger dates or events. These are the points at which the deferred position may crystallise into an actual payment obligation.
• Check the calculation method. The notice should explain how tax is to be worked out on those future dates.
• Review the factual basis. Ask whether anything relevant was omitted from the application, whether anything stated was inaccurate, and whether the underlying facts have since changed.

If there has been a change in the transaction structure, the payment mechanics, the contingency, or any other fact relevant to the original application, you need to consider whether the approval still has effect.

Example

Illustration: a buyer agrees to pay a fixed price for land plus an additional amount if planning permission is granted within a stated period. The buyer applies to defer SDLT on the uncertain additional amount, and HMRC accepts the application.

HMRC’s notice should say:

• what SDLT must be paid with the original return based on the fixed amount;
• the future event or date that matters, such as the grant of planning permission or the end of the relevant period; and
• how the additional SDLT is to be calculated if the extra payment becomes due.

If the original application failed to mention an important part of the payment arrangement, HMRC’s acceptance may have no effect. If the deal is later varied so that the relevant contingency works differently, the approval may cease to have effect because the facts have changed.

Why this can be difficult in practice

The source material is brief, but several points can be fact-sensitive.

First, what counts as a fact or circumstance “relevant” to the application may not always be obvious. The safer reading is that anything material to the deferred tax analysis should have been disclosed.

Second, a change in facts may be straightforward in some cases and less clear in others. A major variation to the transaction terms is an obvious example, but smaller changes may be harder to assess.

Third, the manual describes HMRC’s procedural position. The underlying legal effect depends on the legislation and the actual terms of the acceptance notice. So it is important not to treat a short manual statement as if it were the full legal code.

Key takeaways

• If HMRC approves SDLT deferral, its acceptance notice should state the terms, the tax due with the initial return, the relevant future dates, and the method of calculation.
• An approval is only as good as the facts behind it. False information or failure to disclose relevant matters can mean the acceptance has no effect.
• If the relevant facts later change, the deferral approval may stop applying, so the position should be reviewed whenever the transaction changes.

This page was last updated on 24 March 2026

Useful article? You may find it helpful to read the original guidance here: Guidelines for Deferring Tax Payment on Contingent or Uncertain Land Transactions

View all HMRC SDLT Guidance Pages Here