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How the premium is worked out
A statutory lease extension adds 90 years to the years left and cuts the ground rent to a peppercorn (section 56 of the Leasehold Reform, Housing and Urban Development Act 1993). The landlord is paid for what they give up, in three parts (Schedule 13 of the same Act):
| Ground rent | The rent for the rest of the lease, valued today at a capitalisation rate. We use 6.5%, with a range of 6% to 7%. |
|---|---|
| The landlord’s interest | The flat’s value with a long lease, deferred to the end of the current lease at 5% a year, less the same value deferred to the end of the new lease. |
| Marriage value (80 years or fewer left) | The flat’s value with the new lease plus the landlord’s new interest, less the current lease value and the landlord’s old interest. The landlord takes half. |
The 5% deferment rate for flats has been used since the Sportelli decision, upheld by the Court of Appeal in 2007. For ground rent, 88% of First-tier Tribunal cases the government reviewed used between 6% and 7%, with a mean and median of about 6.5%.
Two things the calculator leaves out usually push a real premium up. The law values your current lease as if you had no right to extend it, which lowers its value and raises the marriage value. A ground rent that rises during the lease is worth more to the landlord than a flat one. A valuer allows for both.
Sources, checked 20 October 2026:
- Leasehold enfranchisement valuation rates (consultation, GOV.UK)
- Leasehold toolkit: England (GOV.UK, published 20 May 2026)
- Leasehold Reform, Housing and Urban Development Act 1993, section 56: the new lease (legislation.gov.uk)
- The same Act, section 60: the landlord’s costs (legislation.gov.uk)
- The same Act, Schedule 13: the premium (legislation.gov.uk)
The 80-year point
Marriage value is paid only when 80 years or fewer are left on the day the notice is served. With 81 years left, a £300,000 flat with £250 ground rent comes to about £9,500. At 75 years the same flat, worth £275,000 as it is, comes to about £18,200, of which £6,779 is the landlord’s half of the £13,558 marriage value.
Many mortgage lenders also set a minimum lease length, which affects whether a buyer can borrow on the flat. Our leasehold and lease extension page explains what lenders look for.
Worked examples
Three flats, worked out with the same rates as the calculator (5% deferment, 6.5% for ground rent).
90 years left, £250 ground rent, £300,000 with a long lease
| Ground rent the landlord stops receiving | £3,833 |
|---|---|
| Fall in the value of the landlord’s interest | £3,670 |
| Half the marriage value | None: more than 80 years left |
| Estimated premium | about £7,500 |
75 years left, £250 ground rent, £300,000 with a long lease and £275,000 as it is
| Ground rent the landlord stops receiving | £3,812 |
|---|---|
| Fall in the value of the landlord’s interest | £7,630 |
| Half the marriage value | £6,779 |
| Estimated premium | about £18,200 |
60 years left, £100 ground rent, £300,000 with a long lease and £250,000 as it is
| Ground rent the landlord stops receiving | £1,503 |
|---|---|
| Fall in the value of the landlord’s interest | £15,862 |
| Half the marriage value | £16,317 |
| Estimated premium | about £33,700 |
Other costs
- Your valuer. A chartered surveyor values the premium before the notice is served, so the figure in it can be defended.
- The landlord’s costs. You pay the landlord’s reasonable legal and valuation costs for the claim (section 60 of the 1993 Act).
- HM Land Registry. A fee to register the new lease, paid separately to the government.
- Stamp Duty Land Tax. It can be due on a premium over £125,000. We check this in your quote.
- Our fee. It is from £750 + VAT, and we confirm it in a written quote before we start. Our fees page lists our published fees.
If the premium is not agreed within two months of the landlord’s counter-notice, either side can apply to the First-tier Tribunal (Property Chamber), and the application must be made within six months of the counter-notice (section 48 of the 1993 Act). The landlord’s costs of the tribunal hearing are not payable under section 60: each side usually pays its own.
The Leasehold and Freehold Reform Act 2024
The rule that you had to own the flat for two years before claiming an extension ended in January 2025. The Act’s other lease extension changes were not in force when we checked on 20 October 2026: an end to marriage value, 990-year extensions and a standard valuation method with rates set by the government.
The government’s consultation on valuation rates ran until 21 October 2026. It says the new method cannot start until the rates are set, and no start date has been announced. Until then, premiums are worked out as this calculator does. We keep this page under review.
Questions people ask
How much does it cost to extend a lease?
The premium depends on the years left, the ground rent and the flat’s value. On a £300,000 flat with £250 ground rent it is about £7,500 with 90 years left, and about £18,200 with 75 years left if the flat would sell for £275,000 as it is. You also pay your own valuer, the landlord’s reasonable legal and valuation costs, an HM Land Registry fee and your solicitor. Our fee is from £750 + VAT, and the premium and these other costs are separate.
What is marriage value?
The extra value a longer lease creates: what the new lease and the landlord’s remaining interest are worth together, less what the old lease and the landlord’s interest were worth before. When 80 years or fewer are left, the landlord is paid half of it on top of the rest of the premium. Above 80 years it is not paid at all.
Should I extend my lease before it reaches 80 years?
Usually it costs less, because no marriage value is paid while more than 80 years are left. The date that counts is the day your notice is served on the landlord, not the day the new lease is signed. If your lease is close to 80 years, speak to a valuer and a solicitor early.
Has marriage value been abolished?
Not yet. The Leasehold and Freehold Reform Act 2024 provides for an end to marriage value, 990-year extensions and a new way of valuing the premium, but those parts were not in force when we checked on 20 October 2026. The government consulted on the rates to use until 21 October 2026, and its consultation says the new method cannot start until the rates are set. Read the consultation on GOV.UK.
How long do I need to own the flat before I can extend the lease?
No minimum any more. The rule that you had to own the flat for two years before claiming a lease extension ended in January 2025 (GOV.UK leasehold toolkit). The lease must have been granted for more than 21 years.
What does the landlord charge on top of the premium?
Under section 60 of the 1993 Act you pay the landlord’s reasonable legal and valuation costs for the claim, usually whether or not the extension goes ahead once the notice is served. The costs of any tribunal hearing are not included: each side usually pays its own.
Can I agree a lease extension with the landlord informally?
Yes. An informal deal can be quicker, but the landlord can set the terms, for example a shorter extension or a ground rent that keeps rising. The statutory route gives 90 extra years at a peppercorn ground rent. Our leasehold and lease extension page explains how we help.
Related pages
Want a solicitor to handle your lease extension?
An estimate of the statutory premium for extending the lease of a flat in England. It is not a valuation: a valuer sets the figure, and the landlord may not agree it. General information on the law in England as of 20 October 2026, not advice on your lease.