Marriage Value in Lease Extensions — Calculator, the 80-Year Cliff, and Abolition Status

The “80-year cliff” is the point at which extending a lease gets suddenly and significantly more expensive. While a lease has more than 80 years left, no marriage value is payable. The moment it falls below 80 years, marriage value is added to the premium — so a lease sitting at, say, 81 or 82 years is worth extending sooner rather than later. Waiting until it crosses 80 can add thousands of pounds to the cost.

Marriage value is, broadly, the difference between the combined value of the interests before the extension and their combined value after — the uplift the extension creates. Under the current statutory basis that uplift is shared 50/50 with the freeholder, and it only enters the calculation for leases under 80 years. Because it turns on professional valuations of the flat with a short and a long lease, the figures are best estimated with a tool and then confirmed by a surveyor. Try our Lease Extension Calculator to see how the premium changes around the 80-year mark.

The Leasehold and Freehold Reform Act 2024 includes provisions to abolish marriage value in lease-extension and enfranchisement premiums. However, those valuation provisions require secondary legislation to commence and were subject to further consultation.

Status (verified 2026-07-05): As of this date, the marriage-value abolition provisions are not yet in force. Under the law in effect today, marriage value is still payable on leases under 80 years. Because commencement dates can change, confirm the current position with LEASE or GOV.UK before you rely on it — and do not delay extending a near-80-year lease on the assumption the rules will change in time.

If your lease is close to 80 years, extending before it crosses the threshold is usually the single biggest cost saving available to you — it removes marriage value from the calculation entirely under current law. If you're buying a flat with a lease near or below 80 years, factor the marriage value into your offer, and consider asking the seller to serve the extension notice before completion. Our freehold-or-leasehold check and ground rent guide help you pin down the tenure first.