DATA-BACKED GUIDE · UPDATED JULY 2026
How much does a lease extension cost in the UK?
Extending a flat lease is one of the more expensive pieces of legal work a homeowner runs into, mostly because several costs stack on top of each other. You pay your own solicitor and valuer, the premium to the freeholder, and often the freeholder's costs too. The real prices below show what leaseholders have actually paid. Leasehold law is complex and changing, so treat this as general information, not legal advice.
The quick version
- A lease extension has several costs stacked together, your solicitor, your valuer, the premium paid to the freeholder, and often the freeholder's own legal and valuation fees.
- On the formal statutory route you are usually responsible for the freeholder's reasonable costs as well as your own, which is why it adds up.
- An informal extension agreed directly with the freeholder can be lighter on fees but gives you less protection on the terms.
- The premium, the price for the extra years, is usually the biggest number and is set by valuation, not by your solicitor.
- Extending before the lease drops below 80 years matters, because 'marriage value' pushes the premium up sharply after that.
Published and surveyed prices
Why the price varies so much
The single biggest factor is how many years are left on the lease, because a short lease means a higher premium and, once you are under 80 years, marriage value is added on top. The value of the flat and the ground rent feed into that premium too. Then there is the route you take, since the formal statutory process gives you set rights but makes you cover the freeholder's costs, while an informal deal depends entirely on what the freeholder will agree. A cooperative freeholder keeps things cheap, whereas a dispute that ends up at a tribunal is far dearer. Location plays its part as well, with higher flat values in and around London pushing every figure up.
How to pay less
- Act before the lease falls below 80 years, because once marriage value applies the premium jumps and the whole exercise costs more.
- Use a solicitor and valuer who specialise in leasehold, since a specialist often secures a better premium and avoids costly mistakes.
- Ask your solicitor to estimate the freeholder's costs too, not just their own, so the full picture is clear from the start.
- Consider whether an informal deal with a reasonable freeholder saves on fees, while weighing up the weaker terms.
- If several flats in the block want to extend, ask whether acting together spreads some of the shared costs.
Common questions
Why do I pay the freeholder's legal fees too?
On the formal statutory route the law makes you responsible for the freeholder's reasonable professional costs as well as your own. That means two sets of solicitor and valuation fees, which is a big reason lease extensions feel expensive. The costs do have to be reasonable, so it is worth querying anything that looks steep before you pay it.
What is marriage value and why does 80 years matter?
Marriage value is extra money the freeholder can claim once a lease has under 80 years left, reflecting the uplift in value from a longer lease. It can add a large sum to the premium, so extending while you still have more than 80 years usually works out much cheaper. Leasehold rules in this area have been changing, so check the current position with a specialist.
Should I use the formal or informal route?
The formal statutory route gives you set rights, a fixed number of extra years and a capped ground rent, but you pay the freeholder's costs. An informal deal can be quicker and cheaper on fees, though the terms are whatever you and the freeholder agree, which may be less favourable. Because the sums are large, a leasehold specialist is worth the consultation.