How to Use the Buy-to-Let Stamp Duty Calculator
The Buy-to-Let Stamp Duty Calculator computes the total SDLT (England/Northern Ireland), LBTT (Scotland), or LTT (Wales) for investment property and second home purchases, including the 5% additional dwellings surcharge that applies in England from October 2024.
Enter the purchase price and select the tax jurisdiction. The calculator applies the standard rates plus the additional dwellings surcharge at every band, clearly showing the standard tax, the surcharge, and the total payable — essential for accurately budgeting a property investment.
A key nuance: the 5% additional dwellings surcharge applies even if you own only one other property — even a tiny share in another property you inherited, for example. There is a refund mechanism if you buy a new main residence before selling your old one and then sell within 3 years.
📊 Worked Example
£280,000 buy-to-let purchase in England (2025):
- Standard SDLT: £4,000 (0% + 2% + 5% bands)
- 5% additional surcharge: £14,000
- Total SDLT: £18,000
- As % of purchase price: 6.4%
Common Use Cases
- ✅ Budgeting total upfront costs for a buy-to-let property purchase
- ✅ Comparing stamp duty costs between different investment property prices
- ✅ Understanding the full cost of the additional dwellings surcharge
- ✅ Calculating stamp duty for a portfolio landlord buying a new property
- ✅ Working out stamp duty when purchasing a holiday let
- ✅ Checking if a stamp duty refund is possible after selling a previous home
Frequently Asked Questions
What is the additional dwellings surcharge?
The additional dwellings surcharge (or additional property surcharge) is an extra stamp duty charge that applies when you buy a residential property and will own more than one property at the end of the transaction. In England, it's 5% (increased from 3% in October 2024) applied on top of standard SDLT at every band.
Do I pay the surcharge if I'm replacing my main home?
If you sell your existing main residence at the same time as buying a new one (completion on the same day), the surcharge doesn't apply. If you complete on the new property before selling the old one, you pay the surcharge, but can claim a refund within 12 months if you sell the old property within 3 years.
What counts as 'owning another property' for the surcharge?
You own another property if you have a legal interest (including a share) in any other residential property anywhere in the world — not just in the UK. This includes inherited shares, overseas properties, and part-owned properties. Only properties worth over £40,000 are counted.
Can I avoid the stamp duty surcharge by buying through a company?
Corporate purchasers pay SDLT at the non-residential/mixed-use rates or the 15% flat rate for properties over £500,000 (if not relieved). This doesn't avoid the additional property issue and has its own complexities. There's no simple way to avoid the surcharge on investment property purchases.
Is stamp duty refundable on buy-to-let properties?
Only in specific circumstances. If you paid the additional dwellings surcharge because you hadn't yet sold your old main residence, and you then sell it within 3 years, you can claim a refund. You cannot reclaim SDLT paid on an investment property simply because you decided not to rent it out.