When does stamp duty start? The SDLT effective date explained
SDLT effective date
Your SDLT effective date is normally the day the property deal completes. It matters because it fixes when SDLT arises and when reporting timing begins.
- Completion is the general rule.
- Special rules can produce a different date.
- Keep documents that prove when completion happened.
Scroll down for the full analysis.
Read the original guidance here:
When does stamp duty start? The SDLT effective date explained
When does stamp duty start? The SDLT effective date explained
Stamp duty land tax usually starts on the day your property deal completes. That day is called the effective date. It sets when SDLT arises and when the reporting timetable begins.
What this rule is about
Most buyers focus on exchange and completion. For SDLT, completion is normally the key date. That distinction can matter if events happen before the sale is finished.
Completion is the usual answer. It is not always the answer.
What the official source says
HMRC’s manual says that the effective date for a land transaction is normally its completion date, while Finance Act 2003 section 119 sets that general rule but allows exceptions. That is the starting point.
- The normal effective date is the completion date.
- That date determines when SDLT arises.
- It also determines when reporting timing starts.
- Other legal rules may set a different date.
What this means in practice
Put the completion date at the centre of your SDLT check, because the date you agreed the deal, paid a deposit, or received keys may not always provide the answer. Check it first.
- Keep a clear record of the completion date.
- Check whether anything unusual happened before completion.
- Use the right date when working out SDLT reporting.
How to analyse it
Start with the simple question: when did the deal complete? Then check whether it falls within one of the exceptions mentioned by HMRC.
- Identify the property deal and its documents.
- Confirm the actual completion date.
- Check whether the deal completed in the normal way.
- Consider whether a special effective-date rule applies.
Example
Amir agrees to buy a flat on 3 April and completes on 28 April. If no exception applies, 28 April is the effective date, and SDLT plus its reporting timing are worked out from that date rather than the day he signed the contract. Use 28 April.
Why this can be difficult in practice
You might think completion always settles the point. It does not. Some types of deal have special rules, and the supplied HMRC page does not list their details, so completion may not settle the issue in every case. Look for the exception.
- Exchange and completion can be weeks apart.
- Unusual contract terms can need closer checking.
- HMRC guidance points to separate material on exceptions.
Key takeaways
- Completion is usually the SDLT effective date.
- The effective date starts the SDLT and reporting clock.
- Check for an exception before relying on completion.
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 119 — sets the effective date of a land transaction
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 source does not explain the exceptions to the normal completion-date rule. Whether one applies depends on the type and facts of the transaction.
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 later documents
- The completion statement and completion date
- Details of any event before completion that may trigger an exception
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 When does stamp duty start? The SDLT effective date explained [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 119 - sets the effective date of a land transaction https://www.legislation.gov.uk/ukpga/2003/14/section/119/2025-11-17 Guidance page from HMRC on this topic (guidance, not law): https://www.gov.uk/hmrc-internal-manuals/stamp-duty-land-tax-manual/sdltm07600 HOW I WANT YOU TO ANSWER 1. Work from the legislation above. Read it before answering. Guidance from HMRC is its 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 source does not explain the exceptions to the normal completion-date rule. Whether one applies depends on the type and facts of the transaction. 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 31 August 2026
Useful article? You may find it helpful to read the original guidance here: When does stamp duty start? The SDLT effective date explained
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