Quick guide to extending your flat lease in London

Lease extensions are a major issue for flat owners in the capital — and if your lease is approaching the 80-year mark, now is the time to act.

London has around 1.23 million leasehold dwellings, representing 38 per cent of the housing stock — far higher than the national average.

From period conversions in Camden to mansion blocks in Mayfair, extending your lease early can help protect your property’s value and future options.

If you’re considering a lease extension, contact our solicitors today to explore your options.

Why lease extensions matter in London

A lease is a diminishing asset. As the years reduce, so does your flat's value — and the cost to extend rises sharply once the remaining term falls below 80 years. This is due in part to 'marriage value', a legal uplift that becomes payable below that threshold.

London property values also mean short leases are more likely to affect mortgage eligibility and buyer appetite. Lenders are often reluctant to fund purchases where the lease is short, making it harder to sell or refinance without extending.

How leasehold developed in the capital

Many of London's most desirable neighbourhoods are built on historic leasehold estates. Areas like Belgravia, Mayfair, and Bloomsbury were developed by aristocratic landowners who granted long leases instead of selling the land outright — a model still in place today.

That legacy, combined with the volume of flats and high-rise developments, means London has a far greater proportion of leasehold properties than anywhere else in the UK. Whether your flat is part of a Victorian conversion or a glass-fronted tower, chances are it's leasehold.

Check how long is left on your lease

If you're unsure how much time remains, check your title register via the HM Land Registry for a small fee. The register confirms when your lease was granted, how long it was for, and how many years are left.

Know who your landlord is

To initiate the lease extension process, you'll need to contact the landlord. Their details should appear on your most recent ground rent or service charge demand. If not, your solicitor can help identify and contact them.

Get a rough idea of the premium

The cost of a lease extension depends on several factors, including how many years are left, the value of the flat, and the level of ground rent. You can use the Leasehold Advisory Service's online calculator to get a rough idea: www.lease-advice.org/calculator

For a more accurate valuation, it's worth instructing a surveyor who regularly handles lease extensions in London. If you would like us to put you in touch with a suitably qualified surveyor who can assist you with this, please let us know, and we will be happy to do so.

Do you qualify for a statutory lease extension?

Most London flat owners can extend their lease under the Leasehold Reform, Housing and Urban Development Act 1993 — the formal or "statutory" route.

You no longer have to wait two years after purchase to qualify. Since January 2025, flat owners can begin the lease extension process as soon as they're registered as owners at HM Land Registry.

Under the formal route, you can:

• Add 90 years to your lease
• Reduce ground rent to a nominal 'peppercorn'
• Follow a strict legal process and timetable that they must adhere to

How the process works

Every lease extension is different, but the typical steps include:

• Valuation – instruct a specialist surveyor to determine the premium
• Legal notices – your solicitor serves a Section 42 notice on the landlord, and the landlord serves a Section 45 Counter-notice (if using the statutory route), or negotiates informally if agreed
• Negotiation – lease terms and premium are negotiated with the landlord
• Completion – once agreed, the new lease is completed and registered

If the landlord refuses or delays, the First-tier Tribunal can be asked to decide.

When to extend

Ideally, well before your lease falls below 80 years. Acting early avoids marriage value, protects your flat's marketability, and gives you more control.

Even if you're not planning to sell, extending your lease early is usually a sensible long-term move — especially in London, where the stakes are high.

Leasehold reform and future changes

Leasehold reform remains a live issue, but meaningful changes are still some way off. While recent reforms have already allowed flat owners to extend sooner after purchase, further proposals to reduce costs and strengthen leaseholders’ rights have been delayed. 

As we’ve covered in our latest article on leasehold reform, these reforms may take time to materialise, so leaseholders should not delay taking action under the current regime.

Need lease extension solicitors in London?

We're based in Lincoln's Inn Fields, supporting leaseholders across the capital with practical advice and fixed-fee lease extension services.

Our solicitors work with clients across London — from Westminster and Kensington to Hackney, Lambeth, and beyond. Whether you're dealing with an individual landlord or a large estate, we can help you understand your options, navigate delays, and secure the best possible outcome.

If your lease is getting short, speak to our friendly team today.