How Much Does It Cost to Extend a Lease? (2026 UK Guide with Worked Examples)
This guide covers leasehold flats in England and Wales and is general information, not legal advice. Scotland has a separate property law system without this form of residential leasehold.
If you own a leasehold flat, extending the lease is one of the most important and most expensive decisions you'll make as an owner. Online calculators give you a number without explaining what drives it or how to make it smaller. This guide does both, with worked examples at different lease lengths and the one deadline that can add thousands almost overnight.
The short answer
There's no fixed price. You pay the freeholder a premium set by valuation, plus fees on both sides. For a typical flat, the total usually runs from a few thousand pounds for a long lease to well over £20,000 for a short one. The premium depends mostly on how many years are left, and it jumps once 80 years or fewer remain. A statutory extension has these cost layers:
| Cost | Who it goes to | Typical figure in 2026 |
|---|---|---|
| The premium | The freeholder | From around £4,000 for a long lease to £30,000 or more for a short one, set by valuation |
| Your valuation fee | Your surveyor | Often £400 to £800 |
| Your legal fees | Your solicitor | Often £1,000 to £2,000 |
| The freeholder's reasonable costs | The freeholder's advisers | Often £1,000 to £2,500 or more, under current law |
The fees are broadly predictable. The premium is where your timing and advice can save, or cost, you thousands, so the rest of this guide focuses on what drives it.
What makes up the premium
The premium isn't a figure the freeholder simply picks. On the statutory route it's built from up to three parts, and they explain exactly why a shorter lease costs more:
| Part | What you're paying for | When it applies |
|---|---|---|
| Loss of ground rent | Compensation for the rent the freeholder will no longer receive, because a statutory extension reduces ground rent to a peppercorn (effectively zero) | Always |
| Reversion | The value of the freeholder getting the flat back when the lease ends. Extending pushes that date 90 years further away, so it's worth less to them today | Always |
| Marriage value | The increase in the flat's value that the extension creates, currently shared 50/50 with the freeholder | Only where 80 years or fewer remain |
The first two rise gradually as your lease shortens. Marriage value is the one that bites, and it only switches on at 80 years. That single fact is the most important thing in this guide.
Worked examples: the cost at different lease lengths
Here's how the premium typically behaves as a lease gets shorter, for a flat worth around £250,000 with a modest ground rent. The figures are illustrative and show the shape of the cost. Your real figure depends on your ground rent, the flat's value and the valuation rates applied, so get a proper valuation before relying on any number:
| Years left on the lease | Marriage value? | Illustrative premium |
|---|---|---|
| 95 years | No | £4,000 to £6,000 |
| 90 years | No | £5,000 to £8,000 |
| 85 years | No | £7,000 to £10,000 |
| 82 years | No, just above the line | £9,000 to £12,000 |
| 79 years | Yes, just below the line | £13,000 to £18,000 |
| 70 years | Yes | £22,000 to £30,000 |
| 60 years | Yes | £35,000 to £50,000 or more |
Look at the jump between 82 and 79 years. The flat is otherwise identical, but crossing the line adds marriage value and several thousand pounds. Below that, the cost accelerates: a 60-year lease can cost up to ten times as much to extend as a 95-year lease. The cheapest lease to extend is the longest one you still have.
The 80-year cliff: the most expensive deadline in leasehold
If you take one thing from this guide, make it this: aim to extend while your lease has more than 80 years left. Once it reaches 80 years or fewer, marriage value is added to the premium and, under current law, you pay the freeholder half of it.
There's an important technical point that protects you. The valuation is fixed at the date you serve a valid formal notice, not the date the deal completes. So if your lease has 81 years left, serving your Section 42 notice (the formal "tenant's notice" claiming the extension) now locks in a valuation above the line, even if the negotiation runs on past it.
Worked example. Maria's flat is worth about £250,000 and her lease has 81 years left. If she serves her notice now, no marriage value applies and her premium might be around £9,000 to £11,000. If she waits 18 months, her lease drops below 80 years, marriage value applies, and her share could add £4,000 to £6,000 or more for the same flat.
One caution: if the notice is later withdrawn, or treated as withdrawn because a deadline is missed, you lose that valuation date. Our guide on whether a freeholder can refuse to extend a lease sets out the statutory timetable.
How to estimate your own cost
There are three levels of accuracy, and each has its place:
- An online calculator. The government-funded Leasehold Advisory Service (LEASE) has a free lease extension calculator that checks your lease length and estimates the premium for a flat. It can't see your full lease terms or apply a valuer's judgement, so treat it as a starting point, not a quote.
- A specialist valuer's report. A leasehold valuer, ideally a member of the Royal Institution of Chartered Surveyors (RICS), will value your flat and give you a realistic premium range and a figure to propose in your notice. This is the number that matters, so get it before you serve notice.
- The negotiated or tribunal figure. After you serve notice, the freeholder responds with their own figure and the valuers negotiate. If they can't agree, the First-tier Tribunal in England, or the Leasehold Valuation Tribunal in Wales, decides. The final premium usually lands between the two opening positions.
Will the leasehold reforms make it cheaper if I wait?
Possibly one day, but not yet, and waiting is a gamble that often backfires. As of October 2026:
- In force: the two-year ownership rule was abolished on 31 January 2025, so you can extend from the day you're registered as owner. If you're buying a flat with a short lease, the seller can serve notice before completion and pass the benefit to you with the lease.
- Not yet in force: the abolition of marriage value, a new standard valuation method, a 990-year extension term at a peppercorn ground rent, and each side paying its own costs. Marriage value still applies today.
- Still to happen: the government's consultation on the valuation rates closed on 23 September 2026, and the rates must then be set in regulations. The High Court dismissed freeholders' challenges to the reforms on 24 October 2025, but the Court of Appeal has given them permission to appeal, and technical flaws in the 2024 Act are due to be fixed by a new Commonhold and Leasehold Reform Bill first.
No commencement date has been set. Meanwhile your lease keeps getting shorter, and if it drops to 80 years or fewer, today's marriage value could wipe out any future saving. Weigh the real numbers for your lease rather than betting on a timetable.
Statutory or informal: the cost trade-off
You can extend a lease in two ways, and the one that looks cheaper often isn't:
- Statutory, by Section 42 notice. Your legal right. You get 90 years added to what's left, and the ground rent drops to a peppercorn. The freeholder can argue about price but can't refuse if you qualify, and a tribunal settles the figure if needed.
- Informal, by private agreement. It can look quicker, but the freeholder sets the terms, may offer fewer years, and there's no tribunal to keep the price fair. Since June 2022 the added years must be at a peppercorn ground rent, but the existing rent can continue for the rest of the original term.
For most flat owners, the statutory route's certainty makes it the better buy. Our guide on freehold and leasehold explains the wider picture, and our collective enfranchisement page covers buying the freehold together with your neighbours.
Related guides
For more on leasehold property and its costs, these guides may help:
- Can a freeholder refuse to extend a lease?
- Freehold and leasehold: what's the difference?
- Things to consider when buying a leasehold property
- What are disbursements in conveyancing?
Frequently asked questions
Why is my lease extension so expensive?
Almost always because your lease has 80 years or fewer left, which adds marriage value to the premium, and you currently pay the freeholder half of it. A shorter term also increases the reversion element. If you're near the line, serving a valid notice quickly stops it getting worse.
How much does it cost to extend a 60 or 70-year lease?
This is where the cost really climbs. For a flat worth around £250,000, a 70-year lease might cost £22,000 to £30,000 in premium alone, and a 60-year lease £35,000 to £50,000 or more. These figures are illustrative, and a valuer's figure for your flat could differ significantly.
Can I extend a lease myself to save money?
You can serve a Section 42 notice yourself, but it's rarely wise. A defective notice can be invalid, and a notice that's withdrawn or lapses means a 12-month wait before you can serve another, usually with the freeholder's costs to pay. The saving on fees is small next to the risk on a premium worth thousands.
Do I have to pay the freeholder's legal and valuation costs?
Under current law, yes. On the statutory route you generally pay the freeholder's reasonable valuation and legal costs on top of your own. The 2024 Act will change this so each side pays its own costs, but that isn't in force yet.
Should I wait for the leasehold reforms to make it cheaper?
Be very careful. Abolishing marriage value, the change that would cut costs most, isn't in force and has no start date. Meanwhile your lease keeps shortening, so decide on today's real numbers, not a promised timetable.
How accurate is an online lease extension calculator?
It's a ballpark, not a quote. A calculator can't apply a valuer's judgement to your flat and lease terms, so its figure can be out by thousands. Use one for a rough idea, then get a valuer's report before you serve notice.
Does any of this apply in Scotland?
No. Scotland has a separate property law system without this form of residential leasehold, so these rights and costs apply in England and Wales only.
Get clear advice on your lease extension
Lease extension costs swing on decisions that are easy to get wrong on your own: when to serve, which route to take and how to handle the 80-year line. Our property team handles statutory and informal lease extensions across England and Wales. Wherever possible we agree a fixed fee for our legal work at the outset, and you'll have a dedicated conveyancer you can contact directly.
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