RICS deferment rate methodology · Updated 2026 · Free & instant
Tool 1 of 4 — jump to Freehold Purchase, Marriage Value or Ground Rent below.
The property type determines which legislation applies.
1993 Act. 90-year extension. Ground rent to peppercorn.
1967 Act. Right to buy freehold at a modest premium.
Enter the freehold value — what the property would sell for with a long or 999-year title.
Enter the unexpired term and current annual ground rent.
Estimate the cost of buying the freehold of your leasehold house.
Marriage value is only payable when your lease has fewer than 80 years remaining.
Calculate the present value of your ground rent stream at the RICS 5% deferment rate.
The premium is the sum of three RICS components: capitalised ground rent, reversion value, and marriage value (for leases under 80 years). Use the calculator above with your property value, lease length, and ground rent for an instant estimate.
Yes. This page includes four tools: a lease extension premium calculator, a freehold purchase calculator, a standalone marriage value calculator, and a ground rent capitaliser, all using RICS methodology.
HMRC doesn't publish a freehold or lease extension premium calculator — its tools cover tax matters like Stamp Duty Land Tax, not enfranchisement valuations. Premium valuations use the RICS deferment rate methodology this calculator applies, which is the same approach professional valuers and surveyors use and that gets cited in First-tier Tribunal cases. If you need an SDLT figure specifically, use our free SDLT calculator.
Yes — "leasehold enfranchisement" is the umbrella legal term covering both routes: extending your lease, or buying the freehold outright (individually or collectively with other leaseholders). This calculator handles both, so it works as a leasehold enfranchisement calculator whichever route applies to you.
A calculator using the correct RICS deferment rate and current relativity tables — as this one does — gets you within a reasonable range of a professional valuation for most straightforward cases. It won't replace a RICS surveyor's formal valuation for the actual negotiation or tribunal submission, but it's accurate enough to budget with and to sanity-check a quote you've been given.
Freehold purchase valuations for a single flat generally follow the same RICS components as a lease extension — capitalised ground rent, reversion value, and marriage value where applicable — but as part of a collective enfranchisement claim if other leaseholders are involved. Use the freehold purchase tool above for an individual estimate, or see our collective enfranchisement guide if you're buying with your building's other leaseholders.
We’ll notify you when 2024 Act provisions come into force and when new premium rates are confirmed.