Why landlords nearly always pay the surcharge
The additional property rules ask a simple question at the moment of completion. Do you own a major interest in more than one dwelling, and are you replacing your only or main residence? A landlord buying a rental while living in their own home answers yes to the first and no to the second, so the surcharge applies.
Even a first time landlord who rents their own home can be caught, because owning one rental and buying a second is enough. Only a landlord who owns no home of their own and is buying a single property escapes, and that is rare in practice.
What it actually costs
Take a typical buy to let at £200,000 in England. The standard tax would be £1,500, being 2% on the slice from £125,000 to £200,000. Add the surcharge of 5% on the whole £200,000, which is £10,000, and the total becomes £11,500. The surcharge is more than six times the underlying tax, which is why it dominates the acquisition costs on smaller properties.
The same £200,000 purchase in Scotland gives ordinary tax of £1,100 plus an Additional Dwelling Supplement of £16,000, a total of £17,100. In Wales the higher rate table gives 5% on the first £180,000, which is £9,000, plus 8.5% on £20,000, which is £1,700, giving £10,700. The regional differences are substantial and worth factoring into where you buy.
The six dwellings rule on portfolio purchases
This is the single most valuable rule for landlords and it is regularly missed. Where you buy six or more dwellings in one transaction, the purchase can be treated as non residential. Non residential rates are far lower, topping out at 5%, and no surcharge applies at all.
Take a block of six flats bought together for £900,000. Treated as residential with the surcharge, the bill would run to well over £70,000. Treated as non residential, the tax is nothing on the first £150,000, 2% on the slice to £250,000 giving £2,000, and 5% on the remaining £650,000 giving £32,500, a total of £34,500. The saving is enormous, and it comes from a rule sitting in the legislation rather than any kind of scheme.
The dwellings must genuinely be separate dwellings and they must be bought in a single transaction or as linked transactions. Buying six flats from six unconnected sellers over several months does not qualify.
Multiple dwellings relief has gone
If you have read older guidance you may have come across multiple dwellings relief, which averaged the price across the number of dwellings and often produced a large saving on smaller portfolio purchases. That relief was abolished for transactions completing on or after 1 June 2024 and it is not coming back.
What has survived is the six dwellings rule described above, and the mixed use treatment described next. Anyone still budgeting on the basis of multiple dwellings relief is working from figures that are two years out of date.
Mixed use property
Where a purchase includes both residential and genuinely non residential elements, the whole transaction is charged at non residential rates and the surcharge does not apply. A shop with a flat above it is the classic example, and it can produce a much lower bill than the residential rates would.
HMRC has become far more aggressive about weak mixed use claims, particularly those based on a paddock, a stretch of grazing land or a small home office. A claim needs a genuine commercial element with real evidence, such as a commercial lease, business rates, or an agricultural tenancy. A speculative claim that fails can leave you with the tax, interest and a penalty on top.
Buying through a company
Many landlords now buy through a limited company for income tax reasons. Stamp duty does not improve when you do. The company pays the surcharge from its very first purchase, and a company buying a single dwelling above £500,000 in England or Northern Ireland can face a flat 17% charge unless property rental business relief applies.
Moving existing properties from personal ownership into a company is a sale for stamp duty purposes, so a full charge including the surcharge normally arises on the market value. Incorporation relief can help with the capital gains side and partnership rules can sometimes reduce the stamp duty, but this is genuinely specialist territory and the wrong step is expensive.
How the cost is treated afterwards
Stamp duty on a property purchase is capital expenditure, not a running cost. It cannot be deducted against your rental profit in the year you pay it, which surprises a lot of new landlords.
What it does do is increase the base cost of the property for capital gains tax. When you eventually sell, the stamp duty you paid on acquisition, along with legal fees and survey costs, reduces the taxable gain. So the relief comes eventually, it just comes at disposal rather than at purchase. Keeping the completion statement safe for the whole period of ownership is therefore important.
Building a property portfolio?
The difference between a well structured purchase and a default one runs into thousands on every deal. We look at the surcharge, the six dwellings rule, mixed use and company structure before you commit.
Frequently asked questions
Do landlords pay extra stamp duty on buy to let?
Yes. A buy to let is an additional property, so the surcharge applies from the first purchase. That is 5% on top in England and Northern Ireland, 8% in Scotland and a separate higher rate table in Wales.
Can I deduct stamp duty from my rental income?
No. Stamp duty on a purchase is capital expenditure. It cannot be claimed against rental profit, but it does increase the base cost of the property and reduces your capital gains tax when you sell.
Is there a way to avoid the surcharge on a portfolio purchase?
Buying six or more dwellings in a single transaction allows the purchase to be treated as non residential, which removes the surcharge entirely and applies much lower rates.
Does multiple dwellings relief still exist?
No. It was abolished for transactions completing on or after 1 June 2024. The six dwellings rule and mixed use treatment remain available.
Is stamp duty lower if I buy through a limited company?
No, it is usually higher. A company pays the surcharge on its first purchase and can face a flat 17% charge on a single dwelling above £500,000 unless property rental business relief applies.