As of 13 August 2026, AI can calculate the Stamp Duty on a house.
Most people should hand this to a purpose-built tool.
Can you do it?
5 minutesto a draft.
15 minutesto something you’d act on.
Cost, all in£0
Skill neededchat-fluent
Who has to check ityou
What the alternative costsNo comparable commercial price is supplied in the available tool data.
If this goes wrong, you budget for the wrong tax bill or complete with an unexpected amount due, and correcting the position may involve your conveyancer or HMRC.
What to actually do
Use a tool built for this
The route this page recommends
Do it yourself
Second choiceA chat interface, chat-fluent skill, and roughly 15 minutes until you can act on the result.
How to actually do it
- Open the GOV.UK guidance and calculator for SDLT, or the relevant Welsh or Scottish government tax page, and identify the jurisdiction that applies to the property.
- Gather the agreed purchase price, expected completion date, property type, whether you will occupy it as your main home, whether you own another residential property and whether you qualify as a first-time buyer.
- Record any lease premium, rent, linked purchase, company purchase, trust arrangement or overseas property ownership that could affect the calculation.
- Paste the prompt into a chatbot and replace each bracketed slot with your facts, stating none where a detail does not apply.
- Check every rate, threshold and buyer-status assumption in the answer against the current official calculator or government guidance dated 2026-08-13.
- Send the calculation and your checked facts to your solicitor or conveyancer before exchange or completion if the transaction is material, unusual or involves an additional property.
Prompt
Calculate the property transaction tax for this purchase using the rules and rates current on 2026-08-13. First identify whether the property is in England or Northern Ireland, Wales or Scotland, then use the correct tax: SDLT, Land Transaction Tax or Land and Buildings Transaction Tax. Do not guess a rate. If you cannot confirm a current rate from GOV.UK or the relevant devolved government website, say that the rate needs checking and do not present a final figure. Show every band, rate and arithmetic step in a table, then give the estimated total in pounds. State the assumptions and ask me for any missing information before calculating. I will provide: jurisdiction: [England and Northern Ireland, Wales or Scotland]; purchase price: £[amount]; completion or transaction date: [date]; property type: [freehold, leasehold or other]; buyer status: [first-time buyer, previous homeowner or other]; whether I will live there as my main home: [yes or no]; whether I own another residential property anywhere: [yes or no]; whether I am buying jointly: [yes or no]; and any relevant lease premium, rent or linked transaction details: [details or none]. Explain which facts could change the result. This is not professional advice. Tell me to have a solicitor, conveyancer or tax adviser confirm the amount before exchange or completion.
Open it prefilled in ChatGPT or Claude, or copy it into Gemini, which takes no prefill link.
Hand it to a person
The distant thirdA person who owns the outcome does this end to end, worth it when the failure is dear.
What it gets wrong
- AI cannot reliably know which UK property tax regime applies unless you provide the property's jurisdiction.
- AI cannot decide from incomplete facts whether an additional-property charge, relief or special rule applies to you.
- AI cannot guarantee that its rates reflect a rule change or the correct transaction date without a current official source.
- AI does not take responsibility for the tax filed or paid; that remains with you and the transaction professionals advising you.
Even on a YES, the friction has a name: real time truth, judgement under ambiguity and stakes of error.
How we scored this
Five axes, each scored nought to two by hand: ten means AI carries the task cleanly, and the thresholds that turn a total into YES, PARTLY or NO are published in the methodology. Each axis name links to its definition.
| Axis | Score (0–2) |
|---|---|
| Output | 2 |
| Inputs | 2 |
| Verification | 1 |
| Liability | 1 |
| Effort delta | 2 |
| Total | 8 / 10 |
The methodology and its thresholds are published in full.
FAQ
- Can ChatGPT calculate Stamp Duty for me?
- Yes, it can do the arithmetic and show the tax bands if you provide the right facts and current rates. Check the result against the relevant government calculator, because the answer changes with jurisdiction, buyer status and property circumstances.
- How do I calculate Stamp Duty on a house in the UK?
- Start by identifying whether the property is in England and Northern Ireland, Wales or Scotland, then gather the price, completion date, buyer status, occupancy plans and other property ownership. Use the relevant government calculator and have your solicitor or conveyancer confirm the result before completion.
- Can AI calculate Stamp Duty for a first-time buyer?
- It can apply a first-time-buyer rule if you provide the facts that establish whether you qualify and the property meets the relevant conditions. Check the eligibility and current rates on the relevant government website rather than relying on the chatbot alone.
- Is AI calculation of Stamp Duty accurate?
- It can be accurate for a straightforward purchase when the inputs and current official rates are correct. It is not professional advice, and a solicitor, conveyancer or tax adviser should check a serious or unusual case.
Nearby answers
Assessed by gpt-5.6-luna (gpt-5.6-luna) on 2026-08-13, second-checked by an independent model. Wrong somewhere? Email [email protected] and it gets re-checked.
The newsletter
AI news, new answers and product picks, straight to your inbox.