How to Extend Your Lease: Process, Costs and Marriage Value

A short lease can make a flat harder to sell, harder to mortgage and more expensive to fix the longer you wait. At Ally Randall Solicitors, our residential property team helps leaseholders understand their leases and options. This guide explains how to extend your lease, the statutory and informal routes, what lease extension cost involves, what marriage value is and when to act, using current rules for flats in England and Wales.

Quick answer: Most leaseholders of flats can extend by negotiating with the landlord (the informal route) or by serving a formal Section 42 notice (the statutory route). A statutory extension currently adds 90 years to your lease and reduces the ground rent to zero. If your lease has 80 years or fewer remaining, marriage value is added to the price, which is why many leaseholders act before that point. Costs depend on your lease and your flat, so any figure here that is not an official rule is marked as an estimate.

What Is a Lease Extension?

A lease extension adds years to your existing lease. Under the Leasehold Reform, Housing and Urban Development Act 1993, qualifying leaseholders of flats can claim a statutory extension. The new lease runs for 90 years plus the years left on your current lease, at a zero (peppercorn) ground rent. The rest of the terms usually stay the same, subject to minor changes.

Who Can Claim a Statutory Lease Extension?

You generally need a long lease, meaning a lease originally granted for more than 21 years, on a flat. The requirement to have owned the flat for two years was removed from 31 January 2025. Leaseholders of houses use different rules, and not every flat qualifies, so ask your solicitor to confirm your eligibility before you start.

The Two Routes to Extend Your Lease

The Informal Route

Under the informal route, you ask your landlord to agree a lease extension voluntarily and negotiate the price and terms. It can be quicker and more flexible, but the landlord is not obliged to offer the statutory terms, so the length, premium and conditions may differ.

The Statutory Route

Under the statutory route, you serve a formal Section 42 notice on the landlord proposing a price and terms. Because errors in the notice can make it invalid, it is advisable to use a solicitor and a valuer. The main stages are:

1. Get a valuation: a surveyor values your lease and advises on the premium to propose.
2. Serve the Section 42 notice: your solicitor serves the notice, which fixes the valuation date.
3. Landlord’s counter-notice: the landlord must respond by the date in your notice, which must give at least two months. The counter-notice accepts or disputes your right and proposes terms.
4. Negotiation: you and the landlord negotiate the premium and lease terms, usually through your surveyors and solicitors.
5. Tribunal if needed: if you cannot agree, either side can apply to the First-tier Tribunal (Property Chamber) to decide the price and terms. The application must be made within six months of the date the counter-notice was due, or the notice is treated as withdrawn.
6. Complete the new lease: once the terms are agreed or the tribunal decision is final, you and the landlord have two months to complete the new lease.

The landlord can also ask for a deposit of 10% of your proposed premium or £250, whichever is greater, at any time after receiving your notice.

How Much Does a Lease Extension Cost?

The cost of a lease extension has several parts:

• The premium: the price paid to the landlord for the new lease
• The landlord’s costs: under the 1993 Act you usually pay the landlord’s reasonable legal and valuation costs
• Your own costs: your solicitor’s fees and your valuer’s fees
• Other costs: HM Land Registry fees and any stamp duty if it applies

There is no standard price. The premium can range from a few thousand pounds to tens of thousands or more (an estimate), depending on the value of your flat, the length of the lease left, the ground rent and where you live. The Leasehold Advisory Service (LEASE) offers a lease extension calculator that gives a rough guide. Always ask a valuer and your solicitor for a figure based on your own lease, and request a written quote for your legal fees.

What Makes Up the Premium?

The premium covers:

• The loss of ground rent over the rest of your lease
• The delay in the landlord getting the flat back, because you are adding 90 years
• Half of any marriage value, if your lease has 80 years or fewer remaining

What Is Marriage Value?

Marriage value is the increase in value created when the lease is extended. You pay it only if your lease has 80 years or fewer remaining on the date you serve your Section 42 notice. It is shared 50/50 between you and the landlord, so you pay half. If you have more than 80 years left, you do not pay marriage value.

Here is a simplified illustration with made-up figures. Suppose your flat is worth £250,000 with the short lease and £280,000 with a long lease. The uplift is £30,000, and half of that is £15,000. A real valuation also includes the landlord’s interest and other factors, and it is done by a qualified valuer, so use this only to understand the idea.

The 80-Year Threshold: When Should You Extend?

Because marriage value only applies when 80 years or fewer remain, many leaseholders aim to extend before they reach that point. If you are close to 80 years, speak to a solicitor and valuer promptly, because the date you serve the notice matters. Shorter leases can also make selling or remortgaging harder, and lenders may be reluctant to lend on a short lease. The length at which this happens varies by lender, so check with yours.

Leasehold Reform: Will Lease Extensions Get Cheaper?

Leasehold law is changing in stages. The Leasehold and Freehold Reform Act 2024 is intended to increase the statutory extension term to 990 years and to abolish marriage value. Reports from legal sources indicate that, as at autumn 2026, these changes are not yet in force and the existing 1993 Act rules still apply. LEASE states that the 990-year change has no confirmed start date. The government also published a draft Commonhold and Leasehold Reform Bill in January 2026.

Waiting for reform carries a risk. If your lease falls below 80 years before the changes start, marriage value would still apply under current rules. Ask your solicitor for the current position before you decide, because the rules can change.

How Long Does a Lease Extension Take?

The statutory process has fixed deadlines, such as a minimum of two months for the landlord’s counter-notice and up to six months before the tribunal deadline. Overall, a statutory extension is commonly estimated to take several months, and longer if the price is disputed or goes to the tribunal. An informal extension can be quicker if the landlord agrees promptly.

Extending Your Lease When You Are Selling

If you are thinking of selling, tell your solicitor about the lease early. A buyer may ask you to extend the lease, or may want a price reduction. In some cases the benefit of a Section 42 notice can be passed to a buyer, so ask your solicitor whether that could help.

Speak to Us About Your Lease

Our residential conveyancing solicitors deal with leasehold sales and purchases, including lease review, ground rent, service charges, lease terms and landlord requirements. If you are considering a lease extension, contact our team to discuss your lease and your options. You can see who would handle your matter on our team page, learn more about Ally Randall Solicitors or browse our legal services.

We act for clients across Northwood Hills, Northwood, Pinner, Ruislip, Eastcote, Harrow and Watford.

This article is general information, not legal advice. Leasehold law is changing and each lease is different, so get advice on your own situation. Figures marked as estimates are approximate.

Ask About Your Lease

Call us on 020 8152 8737 or contact Ally Randall Solicitors to discuss your lease.

Frequently Asked Questions

How do I extend my lease?

You can negotiate an extension with your landlord (the informal route) or serve a formal Section 42 notice (the statutory route). A statutory extension for a flat adds 90 years to your existing lease and reduces ground rent to zero. A solicitor and a valuer should handle the process.

How much does a lease extension cost?

There is no standard price. The cost includes the premium paid to the landlord, the landlord’s reasonable legal and valuation costs, and your own solicitor and valuer fees. The premium can range from a few thousand pounds to tens of thousands or more, which is an estimate, so get a valuation for your own lease.

What is marriage value in a lease extension?

Marriage value is the increase in value created when a lease is extended. You pay half of it to the landlord if your lease has 80 years or fewer remaining when you serve your Section 42 notice. If you have more than 80 years left, you do not pay marriage value.

When should I extend my lease?

Many leaseholders extend before the lease falls to 80 years, because marriage value applies at 80 years or fewer. If your lease is close to that point, speak to a solicitor and a valuer promptly.

Do I need to own my flat for two years before extending?

No. The two-year ownership requirement was removed from 31 January 2025. You still need to qualify, for example by holding a long lease of more than 21 years on a flat.

Will lease extensions get cheaper?

The Leasehold and Freehold Reform Act 2024 is intended to abolish marriage value and extend statutory leases by 990 years, but reports indicate these changes are not yet in force and have no confirmed start date. Existing rules still apply, so ask your solicitor for the current position.