Can you defer stamp duty on a future property payment?
Deferring SDLT on a future payment
A buyer may apply to defer SDLT where an extra property payment depends on an uncertain future event and may be due more than six months later.
- HMRC says applications must reach the Stamp Office within 30 days.
- Known, paid or ascertainable amounts may still need to be paid.
- Check the current regulations before relying on the process.
Scroll down for the full analysis.
Read the original guidance here:
Can you defer stamp duty on a future property payment?
You may be able to delay part of your stamp duty land tax, or SDLT, where part of the price turns on a future uncertainty. This does not happen automatically. Qualifying payments face a strict test. HMRC’s manual says that you must apply quickly.
What this rule is about
In some property deals, the price remains unsettled at completion. Some later payments depend on uncertain events. Planning permission, future turnover or another event may not happen.
This creates a problem. SDLT is normally worked out from the amount paid for the property, but nobody may yet know whether the extra sum will become due.
In some of these cases, the law may allow deferral. It does not remove the tax. Instead, it can delay payment while the position becomes clear.
What the official source says
Finance Act 2003 section 90 allows a buyer to apply to defer tax if the amount due depends on a payment that is contingent or uncertain on the effective date. This is usually the completion date, but the SDLT rules can set another date.
- The payment must be contingent or uncertain when the transaction takes effect.
- A contingent payment depends on whether an uncertain future event happens.
- An uncertain payment has an amount or value that depends on uncertain future events.
- At least one future payment date must fall, or may fall, more than six months after the effective date.
- HMRC’s manual says the application must reach the Stamp Office within 30 days of that date.
- The deferral rule does not apply to rent.
Approval excuses no SDLT already paid. Nor can an applicant use it to excuse tax on an amount that is not contingent and that they can work out when they apply.
An important additional point appears in the manual. Deferral can still be available if any part of the uncertain or contingent amount may be payable after six months, even where another part falls due sooner.
What this means in practice
The key question is not simply whether you will pay more later. What matters is the reason you might pay more. A contingent sum differs from a contractual calculation.
The distinction may sound small, but it can determine whether deferral is available.
- Read the payment clause, not just the headline sale price.
- List every possible extra payment and its possible due date.
- Identify the future event that changes whether, or how much, you pay.
- Pay SDLT on amounts that cannot be deferred.
- Keep evidence for the figures and assumptions in your return.
HMRC’s manual says that an amount does not qualify merely because nobody has yet calculated it. If you can ascertain the amount from facts or a formula already in place, HMRC says you should use your best estimate in the return.
Once the final amount becomes known, HMRC says the buyer should amend the return. The legislation allows a buyer to amend a land transaction return, subject to its separate rules.
How to analyse it
Start with the contract. Labels such as “deferred consideration” or “earn-out” do not settle the answer. The operation of the payment clause is what matters.
- What is the effective date of the purchase?
- What part of the price is fixed and already payable?
- What part depends on an uncertain future event?
- Does the amount itself depend on that future event?
- Can at least one possible payment date be more than six months after the effective date?
- Does any part of the proposed deferral relate to rent?
- Can the amount instead be worked out now, even if nobody has done the maths yet?
- Has the application deadline stated in HMRC’s manual been met?
Section 90 says that regulations cover matters such as timing, the form of an application and how HMRC makes its decision. HMRC’s manual sets out its view of those practical requirements, but it is not the law itself.
Example
Amir buys land for £500,000. The contract also says he will pay £100,000 if planning permission is granted. If permission is refused, he pays nothing. The decision may come eight months after the purchase takes effect.
Because the extra £100,000 depends on an uncertain future event and may become payable more than six months later, it is the type of payment for which section 90 may permit an application to defer SDLT.
Now change one fact. The contract says Amir must pay an extra sum after eight months, calculated by a formula using figures already known on completion. Nobody has calculated it yet. HMRC’s manual says this is not enough for deferral: he should make a best estimate in the return, then amend it when the final figure is known.
Why this can be difficult in practice
Contracts can mix several payment types. They may include fixed instalments, future adjustments and true conditional payments. A single clause may contain several different types of amount. You should not treat them all alike.
- A late payment is not automatically an uncertain payment.
- A payment can be uncalculated but still capable of being worked out.
- A formula may depend on known facts, future facts, or both.
- A payment due within six months may still matter where another uncertain payment may be due later.
- Sending an application late may put the proposed deferral at risk under HMRC’s stated process.
- Paying an amount on account may reduce interest on unpaid SDLT.
This final point matters because interest can arise on unpaid tax. The legislation says that an amount lodged with HMRC reduces the amount on which interest is charged. HMRC’s manual therefore suggests a payment on account where the buyer thinks interest may build up.
Key takeaways
- Deferral is for genuinely contingent or uncertain future payments.
- At least one possible payment date must be more than six months away.
- An amount that can be worked out is not automatically eligible for deferral.
Technical analysis
For advisers, and for anyone who wants to check the law behind this page. You do not need this section to understand the guidance above.
Legislation
- FA 2003 section 51 — contingent, uncertain and unascertained payment rules
- FA 2003 section 87 — interest on unpaid stamp duty land tax
- FA 2003 section 90 — deferring tax on contingent or uncertain payments
- FA 2003 Schedule 10 para 6 — amending a land transaction return
Official guidance
The pages below are HMRC’s guidance. Guidance is not law. It sets out how HMRC reads the legislation, and it is not binding on you, on a tribunal or on a court. Where guidance and the legislation differ, the legislation wins. HMRC can also change or withdraw guidance, and it may not cover your facts.
Where this is not settled
- The supplied material does not verify the current regulations governing the form, timing and acceptance of a deferral application.
- The supplied statutory text is current only to 17 November 2025. The applicable law must be checked for a transaction after that date.
Evidence you would need
This kind of case is decided on the facts of the individual property. These are the records that usually settle it, and the ones an adviser would ask you for.
- The signed contract and any side agreements
- A schedule showing each payment, amount and due date
- The clause explaining what future event affects the payment
- Evidence supporting any estimate used in the SDLT return
- Proof of the effective date and the date any application was sent
Explore this with an AI
Readers often want to test their own situation. Copy the prompt below into ChatGPT, Claude or Gemini. It hands the model the actual legislation for this page rather than letting it answer from memory, and tells it to be explicit about what is uncertain. What comes back is information, not advice – check it against the links above.
I am researching UK Stamp Duty Land Tax (SDLT), which applies in England and Northern Ireland. MY QUESTION Can you defer stamp duty on a future property payment? [Replace this with your own situation: what you are buying, the price, the dates, who the buyer is, and what you plan to do with the property.] THE LAW THIS TURNS ON - FA 2003 section 51 - contingent, uncertain and unascertained payment rules https://www.legislation.gov.uk/ukpga/2003/14/section/51/2025-11-17 - FA 2003 section 87 - interest on unpaid stamp duty land tax https://www.legislation.gov.uk/ukpga/2003/14/section/87/2025-11-17 - FA 2003 section 90 - deferring tax on contingent or uncertain payments https://www.legislation.gov.uk/ukpga/2003/14/section/90/2025-11-17 - FA 2003 Schedule 10 para 6 - amending a land transaction return https://www.legislation.gov.uk/ukpga/2003/14/schedule/10/paragraph/6/2025-11-17 HMRC's guidance page on this topic (guidance, not law): https://www.gov.uk/hmrc-internal-manuals/stamp-duty-land-tax-manual/sdltm50900 HOW I WANT YOU TO ANSWER 1. Work from the legislation above. Read it before answering. HMRC guidance is HMRC's view of the law, not the law, and does not bind a tribunal or a court. 2. Tell me what the rule actually requires, in plain English. 3. Tell me which facts decide the answer, and which facts would change it. 4. Tell me what evidence I would need to support the position. 5. Be explicit about anything unsettled or fact-sensitive. Do not guess. 6. Your training data has a cutoff and SDLT rates and reliefs change at fiscal events. Say so if you are not sure the law is current. POINTS ALREADY KNOWN TO BE UNCERTAIN ON THIS TOPIC - The supplied material does not verify the current regulations governing the form, timing and acceptance of a deferral application. - The supplied statutory text is current only to 17 November 2025. The applicable law must be checked for a transaction after that date. Do not give me a conclusion you cannot support from the provisions above.
Legislation links show Finance Act 2003 as it stood on 2025-11-17. The law may have changed since, and the rules that apply are those in force on the date of your transaction. The official guidance this page is based on is here.
This page was last updated on 1 September 2026
Useful article? You may find it helpful to read the original guidance here: Can you defer stamp duty on a future property payment?
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