How Is Stamp Duty Calculated? UK Examples for 2026
Stamp duty catches a lot of buyers off guard, not because the rates are complicated, but because the way it is calculated is widely misunderstood. Most people assume it works like VAT: one percentage on the full amount. It does not. UK property purchase tax uses a banded system, and once you understand how the bands work, the numbers make much more sense.
This guide walks through the calculation method step by step, with worked examples for different buyer types and regions. If you want the figure for your specific purchase price, use the stamp duty calculator to get a full band-by-band breakdown in seconds.
The Slice Method: How UK Property Tax Actually Works
All three UK property purchase taxes work the same way at a structural level. You pay each rate only on the portion of the purchase price that falls within that band, not on the full price. This is sometimes called the slice method or marginal rate calculation, and it is the same principle used in income tax.
The practical effect is that your effective tax rate is always lower than the headline band rate that applies to your purchase. If the top rate in your calculation is 5%, you are not paying 5% of everything. You are paying 5% of the portion that sits in that band, with lower rates on the portions below it.
This distinction matters because a significant number of buyers overestimate their stamp duty bill. If you have read that the rate is "5%" and multiplied that by your purchase price, the answer you got is almost certainly too high.
How to Calculate SDLT in England and Northern Ireland
Stamp Duty Land Tax (SDLT) applies to residential property purchases in England and Northern Ireland. It is administered by HMRC and must be paid within 14 days of completion.
The standard residential bands in force from 1 April 2025 are:
| Purchase price band | SDLT rate |
|---|---|
| Up to £125,000 | 0% |
| £125,001 to £250,000 | 2% |
| £250,001 to £925,000 | 5% |
| £925,001 to £1,500,000 | 10% |
| Over £1,500,000 | 12% |
Source: HMRC, residential property rates. Effective 1 April 2025.
Worked example: standard buyer at £400,000
Take a standard home mover in England purchasing a property for £400,000. You apply the rates to each slice of the price in turn:
| Band | Rate | Calculation | Tax |
|---|---|---|---|
| £0 to £125,000 | 0% | £125,000 x 0% | £0 |
| £125,001 to £250,000 | 2% | £125,000 x 2% | £2,500 |
| £250,001 to £400,000 | 5% | £150,000 x 5% | £7,500 |
| Total | £10,000 |
The effective rate is £10,000 divided by £400,000, which is 2.5%. The top band rate that applies is 5%, but you only pay 5% on the £150,000 slice above £250,000. The rest is taxed at lower rates.
If you had applied 5% to the full £400,000, you would have arrived at £20,000 — double the actual bill. This is the most common calculation error.
Calculating SDLT for First-Time Buyers
First-time buyers in England and Northern Ireland receive a relief that reduces the tax on lower-priced purchases. From 1 April 2025, the nil-rate threshold for first-time buyers is £300,000. This means no SDLT on the first £300,000, provided the property costs no more than £500,000.
On the portion between £300,001 and £500,000, a rate of 5% applies. If the property costs more than £500,000, the first-time buyer relief is withdrawn entirely and standard rates apply from the first pound.
To qualify, every buyer named on the transaction must be a first-time buyer. If one buyer has previously owned a residential property anywhere in the world, including an inherited property, neither buyer qualifies. The relief is set out under Section 57B of the Finance Act 2003, as amended.
Worked example: first-time buyer at £425,000
| Band | Rate | Calculation | Tax |
|---|---|---|---|
| £0 to £300,000 | 0% | £300,000 x 0% | £0 |
| £300,001 to £425,000 | 5% | £125,000 x 5% | £6,250 |
| Total | £6,250 |
A standard buyer at the same price would pay £8,750, so the relief saves £2,500 in this case. Before April 2025, a first-time buyer at £425,000 would have paid nothing under the temporary thresholds that were in force from September 2022. That period has now ended.
Use the England and Northern Ireland SDLT calculator to check figures for any purchase price under both standard and first-time buyer rates side by side.
Calculating SDLT for Additional Properties
Buyers purchasing a second home, buy-to-let property, or any additional residential dwelling pay a surcharge on top of every standard SDLT band. Since 31 October 2024, that surcharge is 5 percentage points, raised from 3 percentage points by the Autumn Budget 2024. The surcharge applies to the full purchase price from £40,000 upwards.
The additional property bands in England and Northern Ireland are therefore:
| Purchase price band | Standard rate | Additional property rate |
|---|---|---|
| Up to £125,000 | 0% | 5% |
| £125,001 to £250,000 | 2% | 7% |
| £250,001 to £925,000 | 5% | 10% |
| £925,001 to £1,500,000 | 10% | 15% |
| Over £1,500,000 | 12% | 17% |
Worked example: second home at £350,000
| Band | Rate | Calculation | Tax |
|---|---|---|---|
| £0 to £125,000 | 5% | £125,000 x 5% | £6,250 |
| £125,001 to £250,000 | 7% | £125,000 x 7% | £8,750 |
| £250,001 to £350,000 | 10% | £100,000 x 10% | £10,000 |
| Total | £25,000 |
Compare that to the standard rate for the same price: £7,500. The surcharge adds £17,500 to the bill on this purchase. As a useful shortcut, the extra cost from the surcharge is always exactly 5% of the purchase price, because the 5 percentage point addition applies across every band. In this case, 5% of £350,000 is £17,500, which matches the difference.
This shortcut only confirms the extra cost from the surcharge. The base SDLT still needs to be calculated band by band.
Buying before your current home sells
If you complete a purchase before selling your existing property, you will temporarily own two residential properties. The higher additional dwelling rate applies at completion. Once you sell the old property, if that happens within 36 months, you can claim a refund of the surcharge from HMRC. The claim must be made within 12 months of the sale of the old property, or within 12 months of the SDLT filing date, whichever is later. The stamp duty refund page covers how to claim and what evidence HMRC requires.
How to Calculate LBTT in Scotland
Scotland uses Land and Buildings Transaction Tax (LBTT) rather than SDLT. It is administered by Revenue Scotland and uses different bands to England. The same marginal calculation principle applies.
| Purchase price band | LBTT rate |
|---|---|
| Up to £145,000 | 0% |
| £145,001 to £250,000 | 2% |
| £250,001 to £325,000 | 5% |
| £325,001 to £750,000 | 10% |
| Over £750,000 | 12% |
Source: Revenue Scotland, LBTT rates and bands.
First-time buyers in Scotland get a raised nil-rate threshold of £175,000 with no upper purchase price cap. The saving compared to standard rates is modest at a maximum of £600, but the absence of any price cap is a meaningful difference from the English system.
For additional properties in Scotland, the Additional Dwelling Supplement (ADS) applies. Since 5 December 2024, the ADS rate is 8%. Importantly, the ADS is calculated differently to the English surcharge. It is 8% of the entire purchase price, added to the standard LBTT total. It is not applied band by band. On a £300,000 second home in Scotland, the ADS alone is £24,000.
Worked example: standard buyer in Scotland at £300,000
| Band | Rate | Calculation | Tax |
|---|---|---|---|
| £0 to £145,000 | 0% | £145,000 x 0% | £0 |
| £145,001 to £250,000 | 2% | £105,000 x 2% | £2,100 |
| £250,001 to £300,000 | 5% | £50,000 x 5% | £2,500 |
| Total LBTT | £4,600 |
The equivalent SDLT in England on the same price would be £5,000. Scotland is cheaper at this price point, largely because the nil-rate band extends to £145,000 rather than £125,000. For properties above £325,000, Scotland becomes more expensive, as the 10% band applies from that point rather than from £925,001 as in England.
Use the Scotland LBTT calculator for a full breakdown including the ADS where applicable.
How to Calculate LTT in Wales
Wales uses Land Transaction Tax (LTT), administered by the Welsh Revenue Authority. Wales has the highest nil-rate threshold in the UK at £225,000, and no first-time buyer relief scheme. The LTT return must be filed within 30 days of completion, not 14 days as in England.
| Purchase price band | Standard LTT rate |
|---|---|
| Up to £225,000 | 0% |
| £225,001 to £400,000 | 6% |
| £400,001 to £750,000 | 7.5% |
| £750,001 to £1,500,000 | 10% |
| Over £1,500,000 | 12% |
Source: Welsh Revenue Authority, LTT rates and bands.
For additional properties, Wales applies a completely separate set of higher residential rate bands rather than adding a flat surcharge to the standard rates. These were updated on 11 December 2024. Because the two rate structures are entirely different, you cannot calculate an additional Welsh property bill by applying a percentage addition to the standard total. Use the Wales LTT calculator to get the correct figure.
Worked example: standard buyer in Wales at £300,000
| Band | Rate | Calculation | Tax |
|---|---|---|---|
| £0 to £225,000 | 0% | £225,000 x 0% | £0 |
| £225,001 to £300,000 | 6% | £75,000 x 6% | £4,500 |
| Total LTT | £4,500 |
The equivalent bills on this purchase elsewhere: SDLT in England would be £5,000, and LBTT in Scotland would be £4,600. For lower-priced properties Wales is competitive due to the high nil-rate threshold, but the 6% rate that kicks in above £225,000 is steep compared to England's 2% band.
Common Calculation Mistakes to Avoid
A few errors come up repeatedly when buyers try to work out their stamp duty manually.
Applying a flat rate to the full price. As covered above, stamp duty does not work this way. Each band applies only to the portion of the price within it. Multiplying the headline rate by the purchase price will give you a figure that is almost always too high.
Using out-of-date thresholds. The nil-rate threshold in England returned to £125,000 on 1 April 2025 after being temporarily raised to £250,000 from September 2022. If you use a calculation tool or guidance that has not been updated, you may see the old figure. The rates on this site are kept current.
Missing the additional dwelling surcharge. The surcharge of 5 percentage points applies to any buyer who will own more than one residential property after completion. This includes buying a new home before the old one has sold, buying a holiday home, and buy-to-let purchases. The surcharge applies even to the nil-rate band in England, so the first £125,000 of a second home is taxed at 5% rather than 0%.
Getting first-time buyer eligibility wrong. The relief does not apply if any buyer named on the transaction has ever owned a residential property, anywhere in the world. Inherited property counts, even if it was sold immediately. If you are buying jointly, both of you must be first-time buyers.
Forgetting that Wales uses different rules for additional properties. Unlike England, which applies a flat 5 percentage point surcharge on top of standard rates, Wales has a completely separate higher residential rate band structure. You cannot estimate a Welsh additional property bill by adding 5% to the standard total.
Frequently Asked Questions
Do you pay stamp duty on the full purchase price or just the amount above the threshold?
You pay on the full purchase price, but using the banded system. Each band's rate applies only to the portion of the price within that band. The nil-rate threshold means you pay nothing on the slice of the price up to that threshold, but the portion above it is taxed at progressively higher rates. You are not exempt from all stamp duty simply because the property is above the nil-rate threshold.
How do I calculate stamp duty on a property that costs exactly £250,000 in England?
At exactly £250,000, a standard buyer pays: 0% on the first £125,000 (£0), then 2% on the next £125,000 (£2,500). Total: £2,500. A first-time buyer at that price pays nothing, as the full £250,000 falls within the first-time buyer nil-rate threshold of £300,000.
Is stamp duty calculated on the mortgage amount or the purchase price?
Stamp duty is calculated on the full purchase price stated in the contract, not on the mortgage amount. If you are buying a £400,000 property with a £320,000 mortgage and an £80,000 deposit, the SDLT is calculated on £400,000.
Does the additional dwelling surcharge apply if I am just moving home but have not yet sold?
Yes. If you own an existing property and complete the purchase of a new one before the old property sells, the additional dwelling surcharge applies at completion. If you then sell the previous property within 36 months, you can claim a refund. See the stamp duty refund page for eligibility and how to apply.
Can I calculate stamp duty myself without a calculator?
Yes, though it takes a few steps. Identify which portion of the purchase price falls within each band, multiply each portion by the relevant rate, then add the results together. The worked examples in this article show the method. The main risk is using out-of-date thresholds or the wrong buyer type, which is why running the figures through the stamp duty calculator as a check is worthwhile even if you have done the maths manually.
Is stamp duty the same across the whole of the UK?
No. England and Northern Ireland use SDLT with a nil-rate threshold of £125,000. Scotland uses LBTT with a nil-rate threshold of £145,000. Wales uses LTT with a nil-rate threshold of £225,000. The band rates, surcharges for additional properties, and first-time buyer reliefs differ in each jurisdiction. Tax is based on where the property is located, not where the buyer lives.
How soon does stamp duty have to be paid after completion?
In England and Northern Ireland, the SDLT return must be filed and the tax paid to HMRC within 14 days of completion. In Scotland, the LBTT return must be filed with Revenue Scotland within 30 days. In Wales, the LTT return must be filed with the Welsh Revenue Authority within 30 days. In practice your solicitor handles this as part of the conveyancing process.
Disclaimer: The calculations in this article and the figures produced by this calculator are estimates based on current published rates. They are not a substitute for legal or tax advice. Always confirm the final stamp duty amount with your solicitor or licensed conveyancer before completion, as rates can change and individual circumstances may affect the amount due.
Written by Ali Walton. Last updated June 2026.
Ali Walton
Ali Walton writes clear, practical UK property tax guides for buyers, homeowners, and investors using current stamp duty, SDLT, LBTT, and LTT rules.