Lease Extension Calculator 2026/27

Calculation runs based on standard HMRC rules.

Deductions are calculated and adjusted accordingly.

Frequently Asked Questions

Why should I extend my property lease and when is the best time?

A leasehold property gives you the right to occupy a property for a fixed term, after which ownership reverts to the freeholder. As the lease gets shorter, the property’s market value decreases, and it becomes increasingly difficult to secure a mortgage. The critical threshold for lease extensions is 80 years. If the remaining term falls below 80 years, the cost to extend the lease increases dramatically. This is because lenders and freeholders include ‘marriage value’ (the increase in the property’s value when the lease is extended) in the pricing, and by law, you must pay the freeholder 50% of this marriage value to secure the extension. Therefore, you should always aim to extend your lease before it reaches the 80-year mark.

What is the statutory lease extension process in the UK?

Under the Leasehold Reform, Housing and Urban Development Act 1993, flat owners have a legal right to a statutory lease extension once they have owned the property for at least two consecutive years. This statutory route grants you an additional 90 years on top of your current remaining lease term and reduces your ground rent to a ‘peppercorn’ (meaning zero ground rent for the rest of the term). The process involves hiring a specialist leasehold surveyor to value the premium, serving a Section 42 Tenant’s Notice to the landlord, and negotiating the final price. Alternatively, you can negotiate an informal lease extension directly with the freeholder, but this lacks statutory protections and may keep ground rent clauses in place.