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Key Concepts

Marriage Value Explained: The Hidden Cost in Lease Extensions

Reading time: 7 min·Last reviewed 20 October 2026·Written by Rahul Tandon, Founder·Primary sources

Marriage value is the most misunderstood, expensive part of a lease extension premium for short leases. Learn how it's calculated and when it's abolished.

Quick Answer Marriage value is 50% of the extra value created when a short lease and the freehold are combined through an extension. It only applies once the lease has 80 years or fewer left on the date of your section 42 notice, and on a £400,000 flat it runs from about £10,000 at 80 years to over £40,000 at 40 years. Above 80 years no marriage value is payable.
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2026 Reform update Marriage value abolition and the 990-year standard lease extension are already law under the 2024 Act, just not yet commenced (only about ten of its provisions are in force). Separately, the Draft Commonhold & Leasehold Reform Bill 2026 proposes to cap ground rent at £250 and ban leasehold for new flats. About the 2024 Act →  |  About the 2026 Bill →  |  Should I wait or extend now? →

What Is Marriage Value?

Part of the Lease Extension series: How Lease Extension Premiums Are Calculated →

Marriage value is the part of a lease extension premium that most often surprises leaseholders, because it does not exist at all until your lease has 80 years or fewer left, and then it can become the largest single component. The rest of this guide explains what it is, how it is measured, how big it gets, and what the law says about abolishing it.

What Is Marriage Value?

A short lease and the freehold are worth less separately than a long lease would be. When you extend, the two interests are effectively “married”: your lease becomes long, the freeholder's interest shrinks to a distant reversion, and the combined value of the two goes up. Marriage value is that increase, and under Schedule 13 to the 1993 Act the freeholder is entitled to 50% of it, with the leaseholder keeping the other half.

It is payable only where the unexpired term at the valuation date is 80 years or fewer. The valuation date is the date your section 42 notice is served, not the date the extension completes. That is why a lease at 81 years pays no marriage value at all while the same lease at 80 years pays about £10,000 on a £400,000 flat (see the table below).

Marriage value is the reason an extension costing about £11,500 with 81 years remaining could cost about £22,000–£23,000 with 80 or 79 years remaining — for the same property and the same transaction.

The Formula

Marriage value = (extended lease value + freeholder's interest after extension) − (current lease value + capitalised ground rent + freeholder's current reversion)

The freeholder receives half of that figure. To value the current lease you need a relativity: the percentage of the freehold value that a lease of that length is worth. We use the Gerald Eve 2016 table (about 86% at 72 years, 70.5% at 50 years). The extended lease (existing term plus 90 years) is valued at about 98–98.5% of freehold value. See our guide to relativity tables for how these are used and disputed.

A Worked Example

Property freehold value: £400,000 | Unexpired lease: 72 years | Ground rent: £200/yr

  • Current lease: Gerald Eve 2016 relativity at 72 years is about 86.1%, so the existing lease is worth about £344,400
  • Extended lease (162 years): about 98.5%, so about £394,000
  • Freeholder's current reversion: £400,000 ÷ 1.0572 = about £11,900 | Ground rent capitalisation: about £3,880
  • Total marriage value = (£394,000 + about £150) − (£344,400 + £3,880 + £11,900) = about £33,900, of which the freeholder takes 50% = £16,960
  • Total premium: £11,780 (reversion) + £3,880 (ground rent) + £16,960 (marriage value) = about £32,600

Same method and inputs as our calculator, at 5% rates. A surveyor may use different rates or relativity evidence.

How Marriage Value Grows as the Lease Shortens

For a £400,000 flat with £200 ground rent, our calculator gives:

Years leftMarriage valueTotal premium
81£0about £11,500
80about £10,100about £21,900
75about £14,200about £28,300
70about £18,700about £35,600
60about £28,100about £53,000
50about £37,000about £75,100
40about £43,200about £102,700

Two things stand out. First, the jump at the 80-year line is abrupt, which is why timing the notice matters (see below). Second, marriage value alone does not explain the rising cost: the reversion grows too as the lease shortens, so the whole premium accelerates. Figures scale with property value, so a £800,000 flat will cost roughly double.

Why the Relativity Is Disputed

Marriage value is very sensitive to the relativity used for the current lease, because it is the biggest input to the existing lease value. On the 72-year example above, a relativity of 83.1% instead of 86.1% would push marriage value up from about £17,000 to about £23,000, while 89.1% would bring it down to about £11,000. Freeholders' surveyors tend to argue for lower relativities, leaseholders' for higher ones. Since Sloane Stanley Estate v Mundy (2016), tribunals have preferred real-world evidence of comparable sales to rely on graphs alone, so a valuer with current evidence is worth paying for. See also how the premium is calculated.

How to Avoid or Limit Marriage Value

  • Serve the notice while you still have more than 80 years. The valuation date is the date of the section 42 notice, so you do not need to complete before the 80-year line, only to serve. Do not leave it to the last month, because you need time to take advice and prepare.
  • Buy with the extension in mind. If you are purchasing a flat with a lease close to 80 years, take advice before exchange. An assigned or newly bought lease can be extended straight away now that the two-year ownership rule has gone (removed on 31 January 2025).
  • Consider collective action. In a building where many leases are short, marriage value is a big component of the price of the freehold too; see collective enfranchisement.
  • Negotiate on evidence. A well-evidenced relativity argument can move marriage value materially.

Will the 2024 Act Abolish It?

The Leasehold and Freehold Reform Act 2024 provides for marriage value to be abolished for residential lease extensions and enfranchisement, but that provision is not yet in force and there is no confirmed commencement date. Commencement depends on the government setting the new valuation rules by regulations, and the government has been consulting on the valuation rates (the consultation closes on 21 October 2026). Until the relevant provisions are commenced, marriage value is payable under the current rules.

Should You Wait for Reform?

If abolition is implemented, a leaseholder with a 70-year lease on a £400,000 flat would save about £18,700 of marriage value on our calculator's figures. But no date is confirmed, and every year you wait the reversion (and, if you cross below 80, the marriage value) goes up, which can cancel out the saving. Do not rely on reform arriving in time; get specialist advice before deciding. See Should I wait or extend now?

Frequently Asked Questions

Marriage value 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 that increase. It is only payable where the unexpired term at the valuation date is 80 years or fewer.

When the unexpired term is 80 years or fewer on the date your section 42 notice is served. Above 80 years there is none. On a £400,000 flat with £200 ground rent our calculator shows no marriage value at 81 years and about £10,100 at 80 years, which is why serving the notice before the lease falls to 80 years can save a large sum.

It depends on the property value, the lease length and the relativity applied. For a £400,000 flat our calculator gives about £14,200 at 75 years, £18,700 at 70 years and £28,100 at 60 years. It scales roughly with the value of the flat. A surveyor's valuation can differ because of the relativity evidence they use.

The 2024 Act provides for it, but the provision is not yet in force and no commencement date has been confirmed. The government has been consulting on valuation rates, and the consultation closes on 21 October 2026. Until the provisions are commenced, marriage value remains payable. Do not assume it will be abolished before you need to extend.

The notice date. The lease length used for the premium, and for deciding whether marriage value applies, is the unexpired term on the date you serve your section 42 notice, not the date the extension completes. A lease that drops below 80 years during the process does not make the premium higher.

🇺🇸 American buying a UK flat?

The American's Guide to Buying a UK Leasehold Flat

30 pages. Ground rent, the 80-year rule, marriage value, stamp duty, US tax reporting and the 2026 reforms — all in plain American English. Written by Rahul Tandon, LeaseVault founder.

Primary Sources & Statutory References

This guide is researched from official and primary sources. Check them directly before relying on any figure or date.

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