UK SDLT Additional Property Surcharge 2025/26 — the 5% rule

1. How the surcharge actually works

Standard residential SDLT in England and Northern Ireland is charged on a slice-by-slice (progressive) basis. From 1 April 2025 the bands are: 0% on the first £125,000, 2% from £125,000 to £250,000, 5% from £250,000 to £925,000, 10% from £925,000 to £1,500,000, and 12% above. The additional-property surcharge does not use those slices: it is a flat 5% on the entire purchase price, added to whatever the standard SDLT comes out to. That structure makes the surcharge especially punishing at lower price points, because the standard bill on a cheap property may be very small, while the 5% surcharge still applies to the whole consideration.

The Autumn Budget of 30 October 2024 raised the surcharge from 3% to 5% with effect from 31 October 2024. The same Budget also confirmed that the temporary uplift to the nil-rate band — introduced in September 2022 — would expire on 31 March 2025 as scheduled, restoring the £125,000 starting threshold from 1 April 2025. Two structural changes in five months produced a noticeably heavier total burden for landlords and second-home buyers in 2025/26.

2. Worked example — £400,000 second home

A couple already owns the home they live in. They buy a £400,000 second property — perhaps a holiday cottage, perhaps their first buy-to-let. The 2025/26 calculation looks like this:

Note the surcharge alone — £20,000 — is roughly two months of net rent on a typical £400,000 buy-to-let yielding 6%. Combined with Section 24 interest restriction, the higher entry cost has materially reshaped landlord investment maths in 2025/26.

3. Joint purchase rules — the "any purchaser" trap

The surcharge applies if any one joint purchaser would, viewed alone, have to pay it. There is no apportionment by ownership share. Two friends buying a flat together, one of whom already owns a home, pay the surcharge on the entire transaction value — not just on the half belonging to the existing owner.

This produces some genuinely surprising outcomes for unmarried first-time buyers. If one buyer is a true first-time buyer and the other already owns a flat, not only does the couple lose first-time buyer relief (which requires both to qualify), they also pay the 5% surcharge on the full purchase price. Some couples restructure the purchase to a sole name, but mortgage lenders may resist that if both incomes are needed to qualify.

4. The 36-month main-residence sale rule

The surcharge is not intended to catch people who are simply moving home but have not yet completed the sale of their old property. In that situation you pay the surcharge up front at completion of the new purchase, and reclaim it from HMRC once the old main residence is sold — provided the sale completes within 36 months of the new purchase. You also have 12 months from the date of the old sale (or, if later, 12 months from filing the SDLT return) to lodge the refund claim.

The refund route is widely used by chains that break down. Lenders sometimes finance the surcharge with bridging or an explicit "SDLT bridge" facility. Once the old home sells, the refund comes back to you and the bridge is repaid. The interest cost on the bridge is the practical price of a delayed sale.

The replacement test is strict: the property being sold must have been your only or main residence at some point in the three years before the new purchase, and the new property must become your only or main residence. Letting out the new property while continuing to occupy the old one defeats the relief.

5. Non-UK resident buyers — extra 2% on top

Since 1 April 2021, non-UK resident buyers of residential property in England and Northern Ireland pay an additional 2% surcharge. This stacks with the 5% additional-property surcharge, so a non-UK resident company or individual buying a second home in England in 2025/26 pays standard SDLT +5% +2% = standard rates plus a 7% flat add-on. On the £400,000 example above the total would rise to £38,000.

The residence test for SDLT is not the same as the Statutory Residence Test for income tax. For SDLT you are treated as non-resident if you have spent fewer than 183 days in the UK in the 12 months ending on the effective date of the transaction. Refunds are possible if you subsequently meet the day-count test within the following 12 months.

6. Married couples and civil partners

For the purpose of the additional-property test, married couples and civil partners living together are treated as a single economic unit. If either spouse owns any residential property anywhere in the world, both are deemed to own it. The surcharge then bites on any joint purchase, and on any purchase by either spouse alone, unless the new property genuinely replaces their joint main residence.

A common scenario: one spouse owned a buy-to-let before marriage; the couple now wants to buy their first joint home. The buy-to-let counts against both of them, so the joint home purchase pays the surcharge — even though one of the spouses has never owned property before. Selling the buy-to-let on or before completion of the joint purchase avoids the surcharge.

7. Trust ownership

Properties held through trusts are treated as owned by individuals where the trust is a "bare" trust or where the beneficiary has a life interest (interest in possession). The beneficiary is treated as the owner of the underlying property for SDLT surcharge purposes. Discretionary trusts are different — the trustees are the relevant purchasers and the property is generally treated as held by the trustees in that capacity.

A common planning question: a parent settles a property on bare trust for an adult child to receive help on the housing ladder. The child is treated as the owner for SDLT surcharge purposes when later buying another property — so the trust does not shield a future purchase from the surcharge. Conversely, a discretionary trust may help, but it brings its own tax cost (10-yearly IHT charges, exit charges, no Principal Private Residence relief for the beneficiary in many cases).

8. Mixed-use property — the commercial element escape

A property is "residential" for SDLT only if it consists entirely of dwellings (with their grounds). If any part is non-residential — a shop unit, a paddock used commercially, a working farm — the whole transaction is treated as mixed-use and taxed at non-residential rates with no additional-property surcharge at all. Non-residential rates are lower and the bands wider, so mixed-use treatment can be very attractive.

HMRC has tightened up enforcement aggressively. Buying a country house with a small paddock that the seller occasionally let to a neighbour is not mixed-use; the paddock must be genuinely commercial, with documentary evidence of trading use throughout the seller's ownership. The tribunals are full of failed mixed-use claims. Take advice before relying on the classification — and price the risk of HMRC reassessment into your offer.

9. The six-or-more bulk purchase concession

One long-standing SDLT planning route survives the 2024 changes: where a single transaction includes six or more separate dwellings, the buyer can elect to pay SDLT at the non-residential rates on the whole price. The surcharge does not apply to non-residential calculations, so the election strips out the 5% loading and uses the lower commercial bands and rates (top rate 5%).

Until 31 May 2024, large landlords could double-dip by claiming Multiple Dwellings Relief on top of other reliefs, often producing very low effective rates on portfolio purchases. With MDR now abolished, the six-or-more election is the most useful surviving route, but it is only realistic for buyers acquiring an actual block — six flats in one purchase, a development site with completed units, etc.

10. Multiple Dwellings Relief — abolished 1 June 2024

MDR allowed buyers of two or more dwellings in a single transaction to calculate SDLT on the average price per dwelling, with a minimum effective rate of 1%. It was particularly valuable for purchases with annexes, granny flats and stacked units. Following an HMRC review showing high abuse rates, MDR was abolished for transactions with an effective date on or after 1 June 2024. Transitional rules preserve MDR only where contracts were exchanged before 6 March 2024 and not subsequently varied.

Buyers who would previously have relied on MDR — for example, buying a main residence with an annex — now face the full residential SDLT bill plus, in most cases, the additional-property surcharge if the annex is treated as a separate dwelling. The granny-annex rules have become a minefield; HMRC tends to treat structurally connected annexes as part of the main dwelling, which avoids surcharge but removes any planning advantage.

11. Linked transactions

Two or more transactions between the same buyer and seller (or persons connected with them) within a short period are treated as a single transaction for SDLT — the prices are aggregated and SDLT is calculated on the total. The surcharge then applies on the aggregate where applicable. This catches staged purchases — buying a house and an adjacent garage plot in two contracts, for example — and also the splitting of large portfolios.

Linkage applies whether the transactions are between identical parties or merely connected ones. Two separate purchases by a husband and wife from the same vendor are normally linked. The same principle prevents engineering a sequence of below-£40,000 dwelling purchases to avoid the trigger threshold.

12. Scotland and Wales — regional comparison

SDLT is an England and Northern Ireland tax. Scotland and Wales have their own devolved systems with different rates, bands and surcharge mechanics.

Scotland's ADS is the steepest of the three at 8% — a £400,000 second home north of the border carries an ADS of £32,000alone, before standard LBTT. Wales applies higher rates band-by-band rather than as a flat add-on, which softens the impact at the low end and sharpens it at the top. None of the three regimes recognises another region's main residence as displacing the surcharge — a Scottish main home does not exempt your English second purchase, and vice versa.

Northern Ireland uses the same SDLT regime as England and is subject to the 5% surcharge identically. The non-UK resident 2% top-up applies in England and Northern Ireland; Scotland and Wales have their own equivalents (none for ADS, but Wales has consulted on a non-resident loading).

13. Practical planning checklist

• Confirm whether either spouse/partner owns any property anywhere in the world.
• If buying through a Ltd company, assume the surcharge applies — there is no main-residence relief.
• If the property has any non-residential element, take advice on mixed-use classification.
• If replacing a main residence, model the cash-flow gap and the bridging cost.
• If non-UK resident, plan the 183-day post-completion stay to claim the 2% refund where realistic.
• For portfolio purchases of six or more dwellings, model the non-residential election explicitly.
• Document trust beneficial ownership clearly before any new purchase — bare trusts are transparent for the surcharge.
• Watch the 36-month refund window if the chain looks fragile.

14. Official sources

• HMRC guidance: Higher rates of SDLT for purchases of additional residential properties (gov.uk/guidance/sdlt-higher-rates-for-additional-properties).
• HMRC manual SDLTM09730 et seq. — the technical detail on the higher rates.
• HMRC manual SDLTM09812 — refund claims when replacing a main residence.
• Autumn Budget 2024 (HM Treasury, 30 October 2024) — surcharge raised from 3% to 5%.
• Revenue Scotland: Land and Buildings Transaction Tax — Additional Dwelling Supplement.
• Welsh Revenue Authority: Land Transaction Tax higher rates.
• Finance (No. 2) Act 2024 — abolition of Multiple Dwellings Relief.

Bringing it together

The additional-property surcharge is the single biggest line item in the 2025/26 SDLT regime for anyone buying anything other than their only home. A 2-percentage-point increase looks modest until you apply it to a £400,000 or £750,000 purchase price: at 5% the surcharge is a five-figure sum on its own, before any standard SDLT. Combined with MDR abolition and the restoration of the £125,000 nil-rate band from April 2025, the entry cost of a second property is at its highest level in decades. Plan early, model the worst case, and treat the 36-month replacement window as a hard deadline.