Buying a leasehold flat in the UK is fundamentally different from buying a freehold house. When you buy a flat, you're typically buying the right to occupy it for a fixed period — the lease — rather than owning the land and building outright. Get the due diligence wrong and you could end up with a property you can't mortgage, can't sell, or are liable for hundreds of thousands in building repair costs. This guide covers the 7 essential checks to make before you offer on any leasehold flat in the UK.
1. Lease Length: The Three Critical Numbers
70 years is the effective mortgage threshold. Many high-street lenders require at least 70–85 years remaining at the point of mortgage application (not at the end of the mortgage term — meaning a 70-year lease on a 25-year mortgage needs 95 years to be safe with some lenders). Below 70 years, you'll struggle to get mainstream mortgage financing. If lenders are refusing due to the short lease or other property issues, see our mortgage on a property with issues guide.
80 years is the most important number. Once a lease drops below 80 years, you lose the right to extend without paying marriage value — a share of the uplift in the flat's value that the extension creates. This can add tens of thousands of pounds to the extension premium. Always check whether you're buying above or below this line.
90 years is what a statutory extension under the Leasehold Reform, Housing and Urban Development Act 1993 delivers — the freeholder must grant a 90-year extension on top of the current term, at a peppercorn ground rent, once you've owned the property for two years. Budget for extension costs (typically £3,000–£15,000 in professional fees and premium for a lease in the 70–85 year range). For a full walkthrough of the statutory extension process, timelines and premium calculation, see our lease extension UK guide.
2. Ground Rent: The Mortgage Trap
Ground rent is an annual charge paid to the freeholder. Historically, this was a nominal sum (£50–£150/year). However, some developers sold leases with ground rent that doubles every 10–25 years — turning a £250/year charge into £4,000/year within decades.
The mortgage trap: Several lenders (including Nationwide and Halifax) will not lend on properties where ground rent exceeds 0.1% of the property value. On a £300,000 flat, that's £300/year. An onerous doubling ground rent clause can render the property unmortgageable — and unsaleable.
The Leasehold Reform (Ground Rent) Act 2022 banned ground rent above a peppercorn (effectively zero) for all new residential leases granted after 30 June 2022. If you're buying a post-2022 new build, ground rent should be zero. If you're buying a resale flat with an older lease, check the ground rent clause carefully in the lease itself (Section 1, often called the "rent" provisions). For a full breakdown of your rights to challenge ground rent and service charges, see our ground rent and service charges guide.
3. Service Charge: What's Reasonable?
Service charges cover the cost of maintaining communal areas, the building structure, buildings insurance, and (in some buildings) concierge, lifts, or landscaping. There is no legal cap on service charges — they must only be "reasonable" under the Landlord and Tenant Act 1985, Section 19.
| Property Type | Typical Annual Service Charge Range |
|---|---|
| Purpose-built flat, no lift | £800–£2,500 |
| Purpose-built flat, lift and communal areas | £1,500–£4,000 |
| Former local authority block | £800–£3,000 |
| Luxury/concierge building (central London) | £5,000–£15,000+ |
| New-build leasehold (first 5 years) | £1,200–£3,500 |
Right to challenge: If you believe a service charge is unreasonable, you can apply to the First-tier Tribunal (Property Chamber) for a determination. Legal costs are lower than county court but still significant — typically £1,000–£5,000 if you use a solicitor.
Right to Manage (RTM): If at least 50% of qualifying leaseholders in a building agree, they can collectively take over management of the building from the freeholder through an RTM company, without having to prove mismanagement. This can significantly reduce service charges. For a detailed guide to the RTM process, see our right to manage block of flats guide. For details on sinking fund requirements and what a healthy reserve looks like, see our sinking fund leasehold property guide.
4. Major Works: Section 20 Notices
Under Section 20 of the Landlord and Tenant Act 1985, a freeholder must consult leaseholders before carrying out any works costing more than £250 per leaseholder (or any long-term services contract exceeding £100/year per leaseholder). The consultation process involves two formal notices and a 30-day response period.
Before offering, ask the seller whether any Section 20 notices have been served. An active major works programme — particularly for roof replacement, external decoration, or lifts — can mean a bill of £5,000–£50,000 per flat arriving within months of purchase. The seller is only required to disclose this if asked directly via the TA7 (Leasehold Information Form).
5. Cladding and the EWS1 Certificate
The External Wall System (EWS1) certificate is an assessment of whether a building's external wall system meets fire safety standards — a response to the Grenfell Tower fire. It is required by most mortgage lenders for:
- Buildings 18 metres or taller (approx. 6 storeys)
- Some lenders also require it for buildings 11 metres or taller (approx. 4 storeys)
The certificate is obtained by a qualified fire engineer and costs £200–£600 per building (not per flat). Without it, you may not be able to get a mortgage — check before instructing solicitors.
Building Safety Fund (BSF): Where unsafe cladding (ACM/HPL) is present on residential buildings over 11m, the government's Building Safety Fund should cover remediation costs for eligible buildings. Leaseholders in qualifying buildings should not be charged for cladding remediation. Check whether the building is registered with the BSF before committing to purchase.
6. Management Company Quality
The management company (managing agent) appointed by the freeholder determines the day-to-day quality of the building. Ask:
- Are they a member of the ARMA (Association of Residential Managing Agents) or RICS-regulated?
- How many complaints have been made to the Property Ombudsman?
- What is the sinking fund balance? (A sinking fund is a reserve for future major works — a healthy fund of £500–£1,000+ per flat suggests the building is well-managed)
Request the last 3 years of service charge accounts from the seller — these are a legal right under LTA 1985, Section 21.
7. The TA7 Leasehold Information Form: Questions to Scrutinise
The TA7 is a seller-completed form specific to leasehold transactions. Key questions to interrogate:
- Has any Section 20 notice been served in the last 3 years (or is one anticipated)?
- Are there any disputes between leaseholders and the freeholder or managing agent?
- Is there outstanding litigation involving the building?
- What is the current balance of the service charge account?
- Has the property been subject to any enforcement action?
A seller answering "Not known" to multiple questions that they ought to know the answer to (particularly if they've lived there recently) warrants further investigation via your solicitor. For a full guide to what conveyancing enquiries cover on a leasehold purchase, see our conveyancing process UK guide.
When to Walk Away
| Scenario | Recommended Action |
|---|---|
| Lease under 70 years and no lender will proceed | Walk away unless price reflects extension cost |
| Active major works dispute with no resolution in sight | Walk away — you inherit the liability |
| Missing EWS1 on a building over 11m and lender requires it | Do not exchange without written lender confirmation they will proceed |
| Onerous doubling ground rent above 0.1% of value | Only proceed if price is heavily discounted and lender agrees |
| Sinking fund is zero with an aging building | Budget for a major works demand within 2–5 years |
Buying a leasehold flat in the UK rewards thorough due diligence. For a broader comparison of buying a flat vs a house as a first property purchase, see our house vs flat first property guide. For a complete explanation of the leasehold vs freehold distinction and what it means for ownership rights, see our freehold vs leasehold UK guide. For the full conveyancing timeline, SDLT costs, exchange vs completion explained, and a moving day checklist, see our moving house checklist UK guide. Renovate Me's leasehold flat checklist tool lets you track all seven checks, flag risks, and share progress with your solicitor — so nothing falls through the cracks.
For a deep-dive on EWS1 ratings, what happens if you're in a B2-rated building, and how to use the Building Safety Fund and developer pledge to get remediation funded, see our cladding and EWS1 forms guide. For the full ground rent reform picture — why the 2022 Act only covers new leases and what existing leaseholders with doubling clauses must do — see our ground rent reform UK guide.