Flat & Apartment Stamp Duty
Stamp duty on flats and apartments including leasehold SDLT rules, NPV of rent calculations, service charge exclusions, and the difference between lease premium and annual ground rent.
In this article
Key Takeaways
- Flats pay standard residential SDLT rates on the lease premium (purchase price) — same bands as houses
- Additional SDLT may apply on the NPV of ground rent if it exceeds £250 per year, charged at 1% on the excess
- Service charges, maintenance fees, and ground rent admin charges are excluded from SDLT calculations
- First-time buyer relief applies to flats: 0% up to £300,000, 5% on £300,001-£500,000
- New-build flats with high ground rent (escalating clauses) can create unexpected NPV liabilities — check lease terms
- Shared ownership flats have a choice: pay SDLT on market value upfront or on each staircasing step
How Leasehold SDLT Works
Most flats and apartments in England are sold on a leasehold basis. When you buy a leasehold flat, you are acquiring a lease — the right to occupy the property for a fixed term, typically 125 to 999 years. For SDLT purposes, leasehold purchases have two potential taxable components that do not exist for freehold house purchases.
These two components are:
- The lease premium — the price you pay for the flat, taxed at standard residential rates
- The net present value (NPV) of rent — the discounted value of all ground rent payable over the lease term, subject to SDLT if the NPV exceeds £250
For most residential flat purchases, the lease premium drives the SDLT bill. The NPV element is typically small or zero for flats with modest, fixed ground rents. Use our stamp duty calculator to calculate the full amount including any NPV component.
Why are most flats leasehold?
In multi-occupancy buildings, the freeholder owns the building structure and common parts. Individual flat owners hold long leases. Some purpose-built or converted flats are sold as share-of-freehold, where residents jointly own the freehold. These are still classified as leasehold for SDLT purposes if the flat itself is held on a lease.
NPV of Rent Calculation
When you take on a new lease (or an existing lease with more than 7 years remaining), HMRC requires you to calculate the Net Present Value (NPV) of all rent payable over the lease term. This is the discounted sum of future ground rent payments, using a discount rate set by HMRC at 3.5%.
SDLT on the NPV is charged at:
- 0% on the first £250 of NPV
- 1% on NPV above £250
NPV in practice for most residential flats
Most residential flats pay modest ground rent of £100–£300 per year on leases of 125–250 years. Even at £300/year over 125 years, the NPV is approximately £8,200 — just £79.50 in additional SDLT. For many flats the NPV component is negligible, but new-build flats with escalating ground rent clauses can create larger liabilities.
Warning: escalating ground rent clauses
Some new-build leases (particularly pre-2022) contain clauses doubling ground rent every 10–25 years. These can dramatically increase the NPV. A flat with ground rent doubling from £500 to £32,000 over 125 years could face an NPV-based SDLT charge running into thousands of pounds. Always check the lease before exchange.
See our detailed leasehold stamp duty guide for the full NPV calculation methodology and HMRC's worked examples.
Service Charges and Exclusions
A key point of confusion for flat buyers is which amounts attract SDLT. The rule is straightforward: SDLT applies only to the chargeable consideration — the purchase price (lease premium) and the ground rent (via NPV). Certain payments commonly associated with flat ownership are explicitly excluded.
| Payment Type | Included in SDLT? | Reason |
|---|---|---|
| Purchase price (lease premium) | Yes | Primary chargeable consideration |
| Annual ground rent | Via NPV | 1% on NPV above £250 |
| Service charges | No | Excluded as maintenance contributions |
| Ground rent admin fees | No | Excluded as administrative costs |
| Buildings insurance contribution | No | Not rent or premium |
| Reserve fund contributions | No | Not chargeable consideration |
Flat vs House: SDLT Differences
The purchase price SDLT rates are identical for flats and houses. The practical differences arise from tenure type (leasehold vs freehold) and the associated ground rent element.
Buying a flat
- • SDLT on lease premium at standard rates
- • Potential additional NPV charge on ground rent
- • Service charges excluded
- • Longer SDLT return (two elements to calculate)
- • Assigned leases — SDLT on any premium paid
Buying a house
- • SDLT on purchase price at standard rates
- • No ground rent / NPV component
- • Simpler calculation — one taxable element
- • Usually freehold (though leasehold houses exist)
- • No service charge considerations
For the purchase price itself, the SDLT is identical. The flat's leasehold nature adds complexity but rarely adds significantly to the tax bill for standard residential ground rents. See the house stamp duty guide for side-by-side comparison.
First-Time Buyer Relief for Flats
First-time buyer relief applies to flats and apartments exactly as it does to houses. If you have never owned residential property anywhere in the world, you can claim:
- 0% on the first £300,000 of the purchase price (lease premium)
- 5% on £300,001 to £500,000
- No relief if the purchase price exceeds £500,000
Example: £280,000 flat — first-time buyer
0% on full £280,000 (below £300k threshold) = £0
Lease premium SDLT: £0
Standard buyer would pay: £3,100
FTB relief on the NPV element
First-time buyer relief only applies to the lease premium (purchase price). The NPV of ground rent element is still calculated and SDLT charged at 1% on any amount above £250, even for first-time buyers. In practice, this is a small amount for most standard residential leases.
Visit the property types hub to explore further reliefs and see how different buyer circumstances affect your total SDLT bill.
Common Questions
Do I pay SDLT on a leasehold flat?
Yes. Leasehold flat purchases are subject to SDLT on the lease premium (the purchase price) at standard residential rates. If the annual ground rent exceeds £250 per year, SDLT is also due on the NPV of the rent over the lease term at 1% above the £250 threshold.
What if I'm buying an assigned lease (not a new lease)?
Assigning a lease (buying from another leaseholder rather than the freeholder) is still a chargeable transaction. SDLT applies on the premium paid for the assigned lease, at standard residential rates. If the unexpired term is more than 7 years, the NPV of remaining ground rent must also be calculated.
Is stamp duty different for shared ownership flats?
Shared ownership flats have two SDLT payment options. You can either pay SDLT on the full market value of the property at the outset (called market value election), or pay SDLT only on the share you buy initially and then pay further SDLT at each staircasing step. Most buyers use the market value election to avoid paying SDLT multiple times.
Does stamp duty apply to a leasehold extension?
If you pay a premium to extend your lease, that premium is potentially subject to SDLT. The new extended lease term is also considered for the NPV calculation. Lease extensions arranged under the Leasehold Reform Act (statutory route) have specific rules — always get advice from your solicitor before completing a lease extension if you are unsure about the SDLT position.
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Emma Richardson, MRICS
Chartered Surveyor & Property Tax Specialist
Emma Richardson is a RICS-qualified Chartered Surveyor with over 12 years of experience in UK property taxation. She founded Stamp Duty Calculator to help buyers understand the complex world of property transaction taxes.