You have found a buy-to-let, agreed a price, and then someone mentions the surcharge. So how much extra stamp duty do you actually pay, and can you ever get any of it back?
If you are buying an additional residential property in England or Northern Ireland, you pay the normal Stamp Duty Land Tax (SDLT) plus a surcharge on top. Since 31 October 2024 that surcharge has been 5%, up from 3% before the Autumn Budget (gov.uk, higher rates for additional properties). It applies to almost every buy-to-let, second home or holiday let, and it can turn a modest SDLT bill into a large one.
How the surcharge is built
SDLT is a "slice" tax. You pay a rate on the part of the price that falls in each band, not one flat rate on the whole price. The surcharge simply adds 5 percentage points to every band.
Here are the standard residential rates and the buy-to-let rates side by side, for purchases completing in 2025-26 (gov.uk SDLT residential rates).
| Portion of price | Standard rate | Buy-to-let rate (with 5% surcharge) |
|---|---|---|
| Up to £125,000 | 0% | 5% |
| £125,001 to £250,000 | 2% | 7% |
| £250,001 to £925,000 | 5% | 10% |
| £925,001 to £1.5m | 10% | 15% |
| Above £1.5m | 12% | 17% |
One useful shortcut: because the surcharge is a flat 5 points across every band, the surcharge part of your bill is always exactly 5% of the purchase price. The rest is the standard SDLT you would pay on any home.
A worked example: a £280,000 buy-to-let
Say you buy a rental flat for £280,000. Work through the buy-to-let column band by band:
- The first £125,000 at 5% = £6,250
- The next £125,000 (£125,001 to £250,000) at 7% = £8,750
- The final £30,000 (£250,001 to £280,000) at 10% = £3,000
Total SDLT = £18,000, an effective rate of about 6.4% of the price.
Now split it into two parts. The standard SDLT on £280,000, if this were your only home, would be £4,000. The surcharge adds exactly 5% of £280,000, which is £14,000. £4,000 plus £14,000 gives the same £18,000. Seeing the bill as two parts makes the refund rules below much clearer.
If you want to test other prices before you offer, the stamp duty calculator does this band-by-band sum for you and lets you toggle the additional-property surcharge on and off.
The traps that catch people out
1. "I'm buying a home, not an investment" is not enough
The surcharge is not about how you plan to use the property. It is about how many residential properties you own at the end of the day of completion. If you already own one (a let, an inherited share, a home abroad) and you are not replacing your only or main residence, the extra 5% applies even to a property you will live in yourself.
Married couples and civil partners are treated as one unit. If either of you owns another property, the surcharge can apply to the purchase even when only one name is on the new deeds.
2. Replacing a main residence: timing decides the bill
There is an important let-off. If you sell your previous main residence and buy a new main residence, you are "replacing" it, and the surcharge does not apply, even if you own a buy-to-let portfolio alongside it.
The catch is timing. If you complete on the new home before you have sold the old one, you own two homes at the end of that day and HMRC charges the surcharge up front. You are not stuck with it, but you have to pay first and reclaim later.
3. The three-year refund window
If you pay the surcharge because your old main home had not sold in time, you can apply for a refund once it does sell, provided you sell the previous main residence within 36 months of the new purchase (gov.uk, apply for a repayment of the higher rates).
Two deadlines matter:
- You must sell the old main residence within three years of buying the new one.
- You must then claim the refund within 12 months of selling the old home, or within 12 months of the filing date of the SDLT return for the new purchase, whichever is later.
Miss the window and the money is gone, so diarise both dates. The refund is the surcharge part only, which in our example was the £14,000, not the whole £18,000.
4. The £40,000 floor and other edges
- The surcharge does not bite on purchases under £40,000.
- Buying six or more dwellings in one transaction can be treated as non-residential, which uses a different rate table.
- Scotland and Wales run their own taxes. Scotland's Additional Dwelling Supplement and Wales' higher Land Transaction Tax rates follow the same idea but with different bands and percentages. The figures above are England and Northern Ireland only.
A quick checklist before you offer
- Count every residential property you (and a spouse or civil partner) own on completion day.
- Decide honestly: are you replacing a main residence, or just buying another one?
- If two homes will overlap, budget the surcharge now and plan to sell the old home inside three years.
- Model the SDLT into your yield before you commit, not after.
This is general information, not tax or financial advice. SDLT has genuinely fiddly edge cases (trusts, probate, mixed-use, first-time-buyer overlaps), so confirm your own position with a conveyancer or tax adviser, and check the current gov.uk rates before you complete.
The surcharge rarely changes the decision on a good deal, but at 5% of the price it changes the numbers enough to matter. Work it out early, keep the refund clock in mind if you are moving home too, and it stops being a nasty surprise at completion.
