Stamp duty where a property contract is assigned in an exchange
Assigned contracts and exchanges
HMRC’s example shows that stamp duty may be based on market value and land exchanged, not only cash paid at completion.
- Each person’s position is considered separately.
- Plot values can set the higher taxable amount.
- The transaction date and any relief need separate checking.
Scroll down for the full analysis.
Read the original guidance here:
Stamp duty where a property contract is assigned in an exchange
Stamp duty where a property contract is assigned in an exchange
Stamp duty can arise in more than one place when a buyer passes a property contract to someone else and receives land in return. HMRC’s example shows why, when a property contract is assigned and land is transferred in return under connected arrangements, the cash paid at completion may not be the figure used for tax. The wider exchange matters.
What this rule is about
Picture a three-way deal. A agrees to sell Plot 1 to B. Before completion, B assigns its right to buy Plot 1 to C. In return, C transfers Plot 2 to B.
You might think C has simply bought Plot 1 for the cash it pays A. HMRC says the transfer of Plot 2 also matters. That distinction can change the taxable amount by hundreds of thousands of pounds.
This is an exchange, even though the parties do not swap the two plots directly. The law looks at what each person gives and receives across the connected arrangements.
What the official source says
HMRC’s manual gives a worked example in which it explains how, on the facts it states, it considers the legislation to apply; the manual itself is not the law. It is only HMRC’s view.
- A agrees to sell Plot 1 to B for £1 million.
- B pays A a £500,000 deposit.
- B assigns its right under that contract to C.
- C gives Plot 2 to B for that assignment.
- Plot 2 is worth £400,000.
- C pays A the remaining £500,000 on completion.
HMRC says B has a notional transaction for Plot 1. That means the law treats B as having made a transaction for stamp duty purposes, although B does not end up owning Plot 1. HMRC puts its taxable amount at £1 million and says relief may be claimed.
The manual does not say which relief applies. It also does not explain the conditions. So this example does not prove that relief will be available in another deal.
- For B’s purchase of Plot 2, HMRC compares £400,000 with £500,000.
- The £400,000 is Plot 2’s market value.
- The £500,000 is the value HMRC places on B’s right to complete Plot 1.
- HMRC uses the higher figure: £500,000.
- For C’s purchase of Plot 1, HMRC compares £1 million with £900,000.
- The £900,000 is £500,000 cash plus Plot 2’s £400,000 value.
- HMRC again uses the higher figure: £1 million.
What this means in practice
In this type of deal, when land is transferred in return for an assigned right and cash is also paid under the arrangements, that land can count just like cash. Cash alone will not do. A party cannot work out stamp duty by looking only at the bank transfer made on completion.
Market value can also set a higher floor. Here, C pays A only £500,000 at completion. Yet HMRC says C’s taxable amount for Plot 1 is £1 million.
That is the part people get wrong.
- List every payment made under every agreement.
- Include deposits, completion money and land given in return.
- Keep the assignment separate from the final transfer documents.
- Check the value of each plot at the relevant time.
- Do not assume the stated price settles the tax figure.
How to analyse it
Start with the deal as a whole: who had the original right to buy, who took it over, and what did each person give in return? The documents matter more than the label placed on the arrangement.
- Identify the original contract and its agreed price.
- Check whether the original buyer assigned any rights before completion.
- Identify what the new buyer gave for those rights.
- Identify any land transferred back to the original buyer.
- Obtain support for the market value of each property.
- Work out each person’s separate property purchase.
- Compare the applicable amounts as the exchange rule requires.
- Check whether a relief is claimed and whether its conditions are met.
What actually decides the answer? In HMRC’s example, the answer turns not simply on the £500,000 paid at completion but on the full value moving between the parties, including the plot transferred as part of the bargain. The whole exchange counts.
Example
Using HMRC’s figures, B agrees to buy Plot 1 for £1 million, pays a £500,000 deposit, and later gives C the right to complete that purchase in return for Plot 2. C gives B Plot 2. Plot 2 is worth £400,000, and C pays A the final £500,000.
HMRC says B’s taxable amount for buying Plot 2 is £500,000, not £400,000. C’s amount for Plot 1 is £1 million, not £900,000. The comparison with market value produces the higher result in both cases.
Why this can be difficult in practice
These arrangements often involve several documents, different dates and values agreed for commercial reasons. A plot may be more useful to one party than its open-market value suggests. That does not, by itself, answer the stamp duty question.
Because the source uses an older assignment framework, gives no transaction date, and cannot establish the rules governing a later real deal, you must check the legislation in force when the real deal took place before relying on this example. The timing matters.
- A deposit may have a different role from a payment for assigned rights.
- Land may be given for more than one purpose.
- A value in a contract may not match market value.
- The available relief, if any, needs separate checking.
- Later changes to the law may affect the result.
Key takeaways
- An assigned property contract can create stamp duty issues for more than one person.
- Land given in return may count alongside cash.
- Market value may produce a higher taxable amount than the agreed payments.
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 47 — stamp duty treatment for property exchanges
- FA 2003 Schedule 4 para 1 — what counts as payment for a property deal
- FA 2003 Schedule 4 para 5 — working out the taxable amount in exchanges
- FA 2003 Schedule 2A para 5 — working out payment after a contract assignment
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 source does not say which relief B may claim, so it cannot establish that relief will be available in another case.
- The source does not give the transaction date. The correct statutory version must be checked before applying this historic example to a real deal.
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 original sale contract for Plot 1
- the assignment agreement between B and C
- the agreement transferring Plot 2 to B
- proof of the £500,000 deposit and completion payment
- professional valuations of both plots at the relevant time
- the dates of the contract, assignment and completion
- documents supporting any relief claim by B
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 Stamp duty where a property contract is assigned in an exchange [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 47 - stamp duty treatment for property exchanges https://www.legislation.gov.uk/ukpga/2003/14/section/47/2025-11-17 - FA 2003 Schedule 4 para 1 - what counts as payment for a property deal https://www.legislation.gov.uk/ukpga/2003/14/schedule/4/paragraph/1/2025-11-17 - FA 2003 Schedule 4 para 5 - working out the taxable amount in exchanges https://www.legislation.gov.uk/ukpga/2003/14/schedule/4/paragraph/5/2025-11-17 - FA 2003 Schedule 2A para 5 - working out payment after a contract assignment https://www.legislation.gov.uk/ukpga/2003/14/schedule/2A/paragraph/5/2025-11-17 HMRC's guidance page on this topic (guidance, not law): https://www.gov.uk/hmrc-internal-manuals/stamp-duty-land-tax-manual/sdltm21650 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 source does not say which relief B may claim, so it cannot establish that relief will be available in another case. - The source does not give the transaction date. The correct statutory version must be checked before applying this historic example to a real deal. 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: Stamp duty where a property contract is assigned in an exchange
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