Stamp duty where part of your home is used for business
Home offices and SDLT
Working from a room at home will normally not make a property mixed-use for SDLT. A separately run and converted business area may produce a different answer.
- Actual use is only one part of the test.
- Suitability for normal living is crucial.
- Keep evidence of the property at completion.
Scroll down for the full analysis.
Read the original guidance here:
Stamp duty where part of your home is used for business
A home office will not usually turn your purchase into mixed-use property for stamp duty land tax. The harder cases involve homes with a clearly separate business area, such as a surgery. You need to consider more than how a room is used. You must also consider whether it remains suitable for normal living.
What this rule is about
SDLT distinguishes property that is wholly residential from property containing a non-residential part, so the classification can determine which SDLT table governs the entire purchase. It can matter greatly.
The law includes any whole building, or part of one, that people use, or could suitably use, as a home. That raises an important question: has a work area stopped being part of the home?
What the official source says
HMRC’s manual draws a line between working from home and running a separate business area within a house. This is HMRC’s view of the law, not the law itself. Its central point is that business use alone does not decide the answer.
- A study used for office work will normally still be suitable for normal living.
- In that usual home-office case, the building remains wholly residential.
- A practitioner may use a room only as a separate surgery rather than as part of the home.
- Even then, it may still be suitable for living in without alteration.
- Major conversion, specialist equipment or a planning restriction may point the other way.
HMRC gives the example of rooms set aside for a doctor’s surgery, and, if nobody also uses those rooms for living, that separate use matters. Suitability still matters.
Even where the rooms have been kept separate from the home, they may remain residential if someone could readily return them to ordinary domestic use. That can decide the issue.
What this means in practice
You might think that a business address, a desk and a laptop settle the issue when a room appears to serve work rather than domestic life. They do not.
Many people work from a spare room, and, where the room still functions as ordinary domestic space despite a desk, laptop and business address, that usually leaves the SDLT category unchanged. Those signs are not conclusive.
The question becomes sharper where a part of the building has its own purpose and feel. A waiting room, treatment room and separate client entrance may need closer examination. The facts at completion matter most.
- Do not assume a home office creates mixed-use property.
- Do not assume business rates prove that it does.
- Check whether the business rooms can serve ordinary living straight away.
- Check whether the sale included a separate commercial area.
How to analyse it
Start with the building as it stood when you completed the purchase. Labels in an estate agent’s listing help little. The real layout and use carry more weight.
- Identify every room or area used for a business.
- Ask whether occupants used it separately from the living areas.
- Check whether family members also used that space as part of the home.
- Look for physical changes made for the business.
- Consider whether specialist fittings prevent normal domestic use.
- Read any planning condition that limits residential use.
- Decide whether the room could return to normal living use without adaptation.
What actually decides it? The combined picture. People can use a room for work while it still remains part of a home. A permanently altered clinic may be different.
Example
Amira buys a house with a spare bedroom containing a desk, computer and filing cabinet. She uses it for remote work, but it has a normal door, heating and bedroom fittings. Nothing stops it being used as a bedroom. On HMRC’s approach, this is the ordinary home-office position, not mixed-use property.
Now change one fact. The room has been converted into a dental treatment room with fixed specialist equipment, and a planning condition prevents residential use there. That could support a different result if fixed specialist equipment and the planning condition together mean that the space cannot serve ordinary living without alteration. The outcome may differ.
Why this can be difficult in practice
These cases are fact-sensitive. There is no simple rule that says a certain number of business rooms, or a certain type of work, changes the SDLT result. A single feature rarely tells the whole story.
Planning records can be especially important. So can photographs from near completion. Later changes may explain little about the property you actually bought.
- A business name on the address is not enough by itself.
- Separate use does not automatically mean the room ceased to be suitable for living.
- A removable desk differs from fixed specialist medical equipment.
- Minor changes may be easy to reverse; substantial conversion may not be.
- Local tax records are evidence, not a final SDLT answer.
Key takeaways
- A normal home office will usually remain part of the home.
- Business use alone does not settle the SDLT category.
- Layout, conversion, restrictions and completion-day evidence matter.
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 55 — choosing residential or mixed property SDLT tables; choosing SDLT tables for linked property purchases
- FA 2003 section 116 — what counts as residential property for SDLT; including part of a building in the test
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
- There is no fixed list of alterations that automatically makes a room commercial rather than part of a home.
- A room used for business may still be suitable for living in if it can readily return to normal domestic use.
- Planning limits may be important, but their effect depends on the wording and legal effect of the restriction.
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.
- Completion-day floor plan — which rooms formed the home and which were set aside for business
- Dated internal and external photographs — the layout, fittings, access and condition when the sale completed
- Room-by-room record of actual use — whether clients, staff or business activity used a separate area
- Planning permission and planning history — whether residential use was restricted or business use was authorised
- Building regulations approvals and completion certificates — the nature and extent of any conversion work
- Invoices for specialist installations or alterations — whether equipment or works made ordinary living use impractical
- Business rates and council tax records — how the property or part of it was recorded for local taxation
- Land Registry title and filed plan — what land and buildings were included in the sale
- Business advertising, appointment records and insurance documents — whether a distinct business premises operated from part of the building
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 part of your home is used for business [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 55 - choosing residential or mixed property SDLT tables https://www.legislation.gov.uk/ukpga/2003/14/section/55/2025-11-17 - FA 2003 section 55 - choosing SDLT tables for linked property purchases https://www.legislation.gov.uk/ukpga/2003/14/section/55/2025-11-17 - FA 2003 section 116 - what counts as residential property for SDLT https://www.legislation.gov.uk/ukpga/2003/14/section/116/2025-11-17 - FA 2003 section 116 - including part of a building in the test https://www.legislation.gov.uk/ukpga/2003/14/section/116/2025-11-17 Guidance page from HMRC on this topic (guidance, not law): https://www.gov.uk/hmrc-internal-manuals/stamp-duty-land-tax-manual/sdltm00390 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 - There is no fixed list of alterations that automatically makes a room commercial rather than part of a home. - A room used for business may still be suitable for living in if it can readily return to normal domestic use. - Planning limits may be important, but their effect depends on the wording and legal effect of the restriction. 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: Stamp duty where part of your home is used for business
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