Estimate the marriage value on your lease extension · Free & instant
Enter your flat’s freehold value, the years left on your lease and your ground rent.
Marriage value is the extra value created when a short lease and the freehold are combined through a lease extension. Under Schedule 13 to the 1993 Act the freeholder is entitled to 50% of it. The calculator measures it as:
(extended lease value + freeholder’s interest after extension) − (current lease value + capitalised ground rent + freeholder’s current reversion)
The result is zero above 80 years, because marriage value is disregarded when the unexpired term exceeds 80 years on the valuation date, which is the date the section 42 notice is served. The calculator shows the total marriage value and your 50% share.
For a £400,000 flat with £200 ground rent:
| Years left | Marriage value payable | Total premium |
|---|---|---|
| 81 | £0 | about £11,500 |
| 80 | about £10,100 | about £21,900 |
| 75 | about £14,200 | about £28,300 |
| 70 | about £18,700 | about £35,600 |
| 60 | about £28,100 | about £53,000 |
| 50 | about £37,000 | about £75,100 |
The step between 81 and 80 years is the 80-year cliff. Marriage value alone is not the whole story: the reversion also grows as the lease shortens. See marriage value explained for a fully worked example and the 80-year rule for timing.
It is the increase in the combined value of the leaseholder's and freeholder's interests when a short lease is extended. Under Schedule 13 to the 1993 Act the freeholder is entitled to 50% of it. It is only payable where the unexpired term is 80 years or fewer on the date the section 42 notice is served.
The statute disregards marriage value when the unexpired term exceeds 80 years. At 80 years or fewer it is payable in full, so the premium steps up sharply at the line. On a £400,000 flat with £200 ground rent our calculator shows no marriage value at 81 years and about £10,100 at 80.
Serve a valid section 42 notice while the lease still has more than 80 years left. The lease length is fixed at the notice date, so you do not need to complete before the line. Do not leave it to the last few months, because you need time for advice and a valuation.
The 2024 Act provides for it, but the provision is not in force and there is no commencement date. A freeholder legal challenge was dismissed by the High Court in October 2025 and is now before the Court of Appeal. Until commencement, marriage value is payable.
No. It is an estimate using the Gerald Eve 2016 relativity and a 5% rate. A RICS valuer will use sales evidence and may reach a different figure, especially because marriage value is so sensitive to the relativity used.
This calculator’s methodology is reviewed by James Norton MRICS, a Chartered Surveyor and Registered Valuer. Legal and process content is reviewed by Sarah Mitcham, a property solicitor. See our calculator methodology and editorial policy. The calculator provides estimates only and is not a valuation or legal advice.
We’ll notify you when 2024 Act provisions come into force and when new premium rates are confirmed.