The 5% SDLT Surcharge on Second Homes: Every Scenario Explained for 2026

What is the additional dwelling surcharge?

Stamp Duty Land Tax (SDLT) in England and Northern Ireland normally applies on a tiered-band basis, so you pay nothing on the first slice of a purchase and progressively higher rates on higher slices. The additional dwelling surcharge works differently: it is a flat 5% of the entire purchase price, stacked on top of every standard band.

Introduced in April 2016 at 3%, the surcharge was increased to 5% on 31 October 2024 as part of the Autumn Budget. It applies whenever any buyer in a transaction owns another residential property anywhere in the world at the moment contracts complete.

The £40,000 threshold provides a narrow escape: if the property you are buying costs less than £40,000, the surcharge does not apply. In practice this excludes very little outside of lock-up garages, small plots of land, or parking spaces.

What triggers the surcharge?

You pay the surcharge if, at completion, you (or any joint purchaser) own a major interest in another dwelling. A major interest is broadly a freehold or a leasehold with at least 21 years remaining.

Properties that count as another dwelling include:

• Your current main home (even if you are selling it in a chain).
• A buy-to-let property in your name.
• A holiday home in the UK or abroad.
• A property you own but someone else lives in (parent, adult child, tenant).
• A property held in a bare trust where you are the beneficial owner.
• A leasehold flat with 21+ years left on the lease.

The following do not trigger the surcharge:

• Properties worth less than £40,000.
• Caravans, mobile homes, and houseboats.
• Commercial property (offices, shops, factories, land only).
• Properties held inside a pension scheme (SIPP, occupational pension).
• A very small undivided share of a property (less than a major interest, such as a tiny beneficial share under a court order).

Worked examples: England 2025/26 SDLT rates

England's standard SDLT residential bands from 1 April 2025 (after the temporary FTB thresholds reverted):

Example 1: £200,000 buy-to-let flat

Standard SDLT (home-mover):

• 0% × £125,000 = £0
• 2% × £75,000 = £1,500
• Total: £1,500

Additional dwelling (BTL buyer):

• 5% × £125,000 = £6,250
• 7% × £75,000 = £5,250
• Total: £11,500 — an extra £10,000 versus buying as a main residence.

Example 2: £350,000 second home

Standard SDLT:

• 0% × £125,000 = £0
• 2% × £125,000 = £2,500
• 5% × £100,000 = £5,000
• Total: £7,500

Additional dwelling:

• 5% × £125,000 = £6,250
• 7% × £125,000 = £8,750
• 10% × £100,000 = £10,000
• Total: £25,000 — a surcharge premium of £17,500.

Example 3: £600,000 BTL property

Standard SDLT:

• 0% × £125,000 = £0
• 2% × £125,000 = £2,500
• 5% × £350,000 = £17,500
• Total: £20,000

Additional dwelling:

• 5% × £125,000 = £6,250
• 7% × £125,000 = £8,750
• 10% × £350,000 = £35,000
• Total: £50,000 — a surcharge premium of £30,000.

At this level the SDLT alone exceeds 8% of the purchase price — a significant drag on BTL yield calculations, particularly in lower-yield markets.

The 36-month replacement main residence rule

The most commercially important relief: if you are buying a new main home but your old main home has not yet sold at the time you complete, you are treated as an additional dwelling buyer and must pay the 5% surcharge upfront. You can then reclaim it in full once the old property sells — provided you sell within 36 months.

How to claim the refund

1. Pay the full surcharge at completion (your conveyancer handles this via the SDLT return).
2. Sell the old main home within 36 months of the new purchase completion date.
3. Submit a refund claim to HMRC within 12 months of the old property disposal, or within 12 months of the new purchase completion date — whichever deadline is later.
4. HMRC refunds the surcharge plus interest (currently Bank Rate + 0.5%) within 4–8 weeks.

The refund can amount to tens of thousands of pounds. Many home-movers, particularly those caught in a slow chain, are unaware this mechanism exists.

When the 36-month rule does not help

• The old property is held in a spouse's sole name — different beneficial owner, no refund on your new purchase.
• You have already sold the old main home more than 36 months before buying the new one — no refund window at all.
• The new property is not your main residence (e.g. you are buying it for a relative to live in while you continue renting elsewhere).
• You own two properties and both were used as 'main residences' — HMRC will challenge a dual-main-residence claim.
• Scotland: the ADS refund window is only 18 months (not 36), and the property sold must have been your main residence for at least part of the period.

Joint buyers: one owner contaminates the whole purchase

The surcharge operates on the transaction, not on the individual buyer. If any named buyer on the purchase deed owns another residential property, the 5% surcharge applies to the entirepurchase price — not just the owning buyer's share.

The parent-helper trap: A first-time buyer son or daughter cannot afford a mortgage alone, so a parent (who owns their own home) is added to the mortgage and the title. Two consequences follow simultaneously:

• The first-time buyer stamp duty relief is lost (no 0% to £300,000 — standard rates apply instead).
• The 5% surcharge applies to the entire purchase.

On a £300,000 purchase this could cost approximately £15,000 more than a solo FTB purchase with no other property. The standard alternative is a Joint Borrower Sole Proprietor (JBSP) mortgage, where the parent appears on the mortgage application (supporting affordability) but not on the title deeds. No additional dwelling; FTB relief preserved.

Scotland: Additional Dwelling Supplement at 8%

Scotland's Land and Buildings Transaction Tax (LBTT) operates on similar principles to SDLT but with different rates. The Additional Dwelling Supplement (ADS) in Scotland stands at 8% of the entire purchase price from December 2024.

Scotland's higher rate means a £350,000 BTL in Edinburgh attracts ADS of £28,000 versus £17,500 of surcharge for an equivalent property in Leeds. The shorter 18-month refund window for replacement main residences is also considerably tighter — buyers in slow Scottish chains should take particular care.

Wales: Land Transaction Tax higher residential rates

Wales uses a structurally different approach. Rather than adding a flat percentage, Wales applies separate rate bands labelled 'higher residential rates' for additional dwellings:

Example — £320,000 second home in Cardiff (2025/26 LTT):

• 4% × £180,000 = £7,200
• 7.5% × £70,000 = £5,250
• 9% × £70,000 = £6,300
• Total LTT: £18,750

By comparison, the same purchase in England as an additional dwelling would cost £22,500 in SDLT. Wales is slightly cheaper for second-home SDLT equivalent at this price point, though the gap narrows at higher values.

Limited companies and corporate buyers

Companies are subject to the additional dwelling rules automatically — there is no equivalent of the 'replacing your main residence' relief for corporate buyers. The rules are:

• Under £500,000: standard SDLT calculated from £0 (no £125,000 nil- rate band applies to companies), plus the 5% ADS surcharge.
• Over £500,000: the 15% flat rate applies to the entire purchase price, replacing the banded + surcharge calculation. This is a deliberately punitive rate aimed at discouraging corporate hoarding of residential property.

Example — limited company purchases £450,000 residential property:

• Standard SDLT (from £0): 0% × £0 = £0, 2% × £125,000 = £2,500, 5% × £325,000 = £16,250 → £18,750
• ADS surcharge 5%: £22,500
• Total SDLT: £41,250 (approx. 9.2% of purchase price)

Example — limited company purchases £550,000 residential property:

• Flat 15% rate: 15% × £550,000 = £82,500 (15% of price)

The 15% flat-rate threshold makes corporate residential property acquisition above £500,000 extremely expensive. Narrow exemptions apply for property rental businesses (Portfolio Relief) and Purpose-Built Student Accommodation (PBSA), but these require careful structuring and professional advice.

Many BTL investors who use limited companies specifically to avoid Section 24 mortgage interest restrictions face a paradox: the tax advantage on rental income is real, but the higher SDLT entry cost on company purchases makes switching from personal name to limited company mid-portfolio extremely expensive.

Non-UK residents: an extra 2% on top

Overseas buyers purchasing residential property in England or Northern Ireland pay an additional 2% surcharge on top of standard SDLT and the 5% ADS. Introduced in April 2021, this non-resident surcharge applies if the buyer is not present in the UK for at least 183 days in the 12 months before the purchase.

A non-UK-resident buying a £400,000 BTL property in London therefore pays:

• Standard SDLT: £10,000
• ADS (5%): £20,000
• Non-resident surcharge (2%): £8,000
• Total: £38,000 — 9.5% of the purchase price.

Strategic considerations for 2026

Personal name vs limited company

The direction of travel since 2015 has been towards limited company BTL for new purchasers, primarily to escape Section 24 mortgage interest restrictions. The SDLT picture is more nuanced: a personal-name buyer pays lower entry SDLT (nil-rate band applies), whereas a company buyer pays from £0 with full surcharge.

For portfolios valued under £500,000 per property, the Section 24 savings over a 10-year hold typically exceed the additional SDLT entry cost — but only if the investor is a higher-rate taxpayer. Basic-rate taxpayers often find personal-name ownership more tax efficient after all costs are modelled.

Avoiding the parent-trap in joint mortgages

• Gift the deposit. If parents provide the deposit as an outright gift, they are not on the deed, the surcharge does not apply, and the child retains FTB relief. The 7-year IHT clock on the gift starts running.
• JBSP mortgage. The parent is named on the mortgage (which helps affordability) but not on the title. No additional dwelling; FTB relief preserved.
• Guarantor mortgage. Similar principle — parent guarantees but does not co-own.

Chains and the 36-month refund

In England, the 36-month window is long enough to survive most property chains, even slow ones. If you anticipate a delayed sale (probate properties, complex leasehold disposals), it is worth keeping accurate records of the SDLT paid and the timeline. The refund is not automatic — your conveyancer or tax adviser must submit the claim.

Quick comparison: same £400,000 property, four buyer types

Sources

• HMRC: SDLT rates for residential property
• HMRC: SDLT higher rates for additional dwellings
• Revenue Scotland: LBTT Additional Dwelling Supplement
• Welsh Revenue Authority: LTT higher residential rates
• HM Treasury: Autumn Budget October 2024 — ADS increase from 3% to 5%.