Extending the lease on a flat with about 85 years unexpired, worth around £350,000 with a £100-a-year ground rent, typically costs £6,000 to £8,000 in statutory premium plus roughly £2,750 to £4,700 in professional fees before VAT. Call it £8,750 to £12,700 all in. That is the honest shape of the answer in 2026 for England and Wales, which is where this regime runs: Scotland has no leasehold flats and Northern Ireland has its own rules. The premium is driven almost entirely by the unexpired term, the flat's value and the ground rent, and the fee stack catches most leaseholders out because it includes the freeholder's costs as well as their own.
Two things make the number hard to pin down from a web calculator. First, the 80-year boundary: once the unexpired term falls to 80 years or below, an extra valuation component called marriage value applies, and the premium can roughly double. Second, and this catches out almost everyone researching in 2026, many online calculators and guides now assume marriage value has been abolished. It has not. The Leasehold and Freehold Reform Act 2024 abolishes it, but that provision is not in force, and a claim made today still pays it in full.
This page decomposes the premium into its components, works the 80-year cliff with numbers, prices every line of the fee stack including the freeholder's costs you are legally obliged to cover, and sets out what the spend does to your tax position. You can put your own figures through our lease extension premium calculator as you read. If you are weighing an extension against buying the freehold outright, that decision has its own page, our lease extension vs freehold purchase guide; this one is about what the extension route costs.
What a lease extension costs in 2026: the all-in answer
A statutory lease extension on a flat under Chapter II of the Leasehold Reform, Housing and Urban Development Act 1993 buys you a specific product: your existing unexpired term plus 90 years, at a peppercorn (nil) ground rent for the entire new term. On a lease with 84 years left, you come out with 174 years and no ground rent. The government's own leasehold guidance confirms the 90-year figure for flats.
The all-in cost has two layers:
- The statutory premium, calculated under Schedule 13 to the 1993 Act. This is the price of the new lease, and it ranges from a few thousand pounds on a long lease with a small ground rent to tens of thousands on a short lease in an expensive area.
- The professional fee stack, typically £2,750 to £4,700 before VAT. This covers your own solicitor and valuer, the freeholder's solicitor and valuer (which you pay under section 60 of the 1993 Act), and the disbursements and registration fees on completion.
One eligibility point that changed recently and in your favour: you no longer need to have owned the flat for two years before claiming. The two-year rule was abolished with effect from 31 January 2025 by SI 2025/57, commencing section 27 of the Leasehold and Freehold Reform Act 2024. A buyer can serve the extension notice on completion day. That abolition is in force; much of the rest of the 2024 Act, as you will see, is not.
The statutory premium decomposed: term, reversion and marriage value
The premium is not a negotiated market price. It is a statutory valuation under Schedule 13 to the 1993 Act, built from up to three components. Understanding them tells you what drives your number, and why two flats on the same street can face premiums thousands of pounds apart.
1. The term. The freeholder currently has the right to receive your ground rent for the rest of the unexpired term. The new lease reduces that rent to a peppercorn, so you compensate the freeholder for the income stream they lose. The figure is the rent capitalised at a yield, commonly 6% to 8% for a modest fixed rent, over the years left to run. A fixed £100-a-year ground rent capitalises to a modest sum; an escalating rent capitalises to a serious one.
The gap between those two is worth seeing in arithmetic. A fixed £150 a year stays £150 for the whole unexpired term. A £150 rent that doubles every 25 years is £300 by year 25, £600 by year 50 and £1,200 by year 75, and the term component grows with it. This is why the review clause in your lease, rather than the rent on today's demand, is what a valuer reads first.
2. The reversion. At the end of your existing lease, the flat would revert to the freeholder. By adding 90 years you push that day nine decades further away, so you compensate the freeholder for the delay. The value of the flat is discounted back over the unexpired term at the deferment rate, which since the Sportelli decision has stood at 5% for flats. Because of compound discounting, the reversion is tiny on a 120-year lease and grows steadily as the term shortens: £300,000 deferred 84 years at 5% is worth around £5,000 today, but deferred 60 years it is worth around £16,000.
3. Marriage value, only below 80 years. When a short lease and the freeholder's interest are "married" by the grant of a new long lease, the combined value is greater than the sum of the parts, because short leases are worth disproportionately less than long ones. Schedule 13 gives the freeholder 50% of that uplift, but paragraph 4(2A) sets marriage value at nil where the unexpired term exceeds 80 years at the valuation date. Above 80 years, this component simply does not exist. At 80 years or below, it exists in full, and it is usually the largest single component.
The deferment rate itself is one of the things the 2024 Act changes: it hands the Secretary of State power to prescribe the rates, and the consultation on those rates closes on 23 September 2026. Until secondary legislation lands, the post-Sportelli 5% remains the working rate, and nobody can tell you whether prescribed rates will push premiums down or up.
The 80-year cliff: what crossing it costs
The cliff is best seen with numbers. Take Farah, who owns a one-bedroom flat worth about £300,000 with the benefit of a long lease, paying £150 a year in fixed ground rent. The figures below are illustrative ranges built from the Schedule 13 components at a 5% deferment rate and a 7% capitalisation rate, in line with published market examples; her actual premium would come from a specialist valuation.
With 84 years unexpired, the premium has two components:
- Term (£150 a year capitalised at 7% over 84 years): around £2,100
- Reversion (£300,000 deferred 84 years at 5%): around £5,000
- Marriage value: nil, because the term exceeds 80 years
- Illustrative premium: roughly £6,500 to £7,500
The same flat at 79 years unexpired looks very different:
- Term: still around £2,100
- Reversion (£300,000 deferred 79 years at 5%): around £6,400, higher because the reversion is nearer
- Marriage value: on relativity of around 93%, which is where the published graphs sit at that term, the uplift created by the new lease runs to roughly £10,000 to £14,000, and the freeholder takes 50%, so £5,000 to £7,000
- Illustrative premium: roughly £13,000 to £16,000
Five years of lease, roughly double the premium. The gradient continues below 79: relativity, the ratio of short-lease value to long-lease value, falls faster as the term shortens, so marriage value grows faster than the term shrinks.
One timing point is worth more than any negotiation tactic: the valuation date is the date your section 42 notice is given, not the date the extension completes. If your lease has 80 years and 3 months left, serving the notice now fixes the no-marriage-value basis even though the claim will take months to complete. Drifting past the boundary while you gather quotes is the most expensive form of procrastination in leasehold, and it is entirely avoidable.
"But I read marriage value was abolished": what is in force
You may well have read that the Leasehold and Freehold Reform Act 2024 abolished marriage value, and that reading is understandable, because the Act does contain the abolition. What the coverage tends to omit is commencement. The 2024 Act's valuation reforms only take effect when the government makes commencement regulations, and it has not done so. Only three commencement instruments exist under the Act, and none of them touches the valuation provisions. On legislation.gov.uk, the omission of Schedule 13 by section 36(5) of the 2024 Act sits under "changes yet to be applied": a prospective repeal, not a live one. Schedule 13, marriage value included, remains the operative valuation law for every claim made today.
The same applies to the 990-year term. The 2024 Act legislates a fresh 990-year lease in place of the plus-90 extension, but that provision is not in force either; an extension completing in 2026 is your term plus 90 years. And the £250 ground rent cap you may have seen reported belongs to a draft Bill announced in the May 2026 King's Speech, and no Act has enacted it.
For pricing purposes, that resolves into one instruction: value your claim on Schedule 13 as it stands, because the abolition is enacted and uncommenced, so it does not belong in your number. For the provision-by-provision ledger of what is and is not commenced, and for the decision framework on whether to extend now or hold off, see our ledger of what the Leasehold and Freehold Reform Act 2024 has in force.
The professional fee stack, including the freeholder's costs you pay
The premium is only the headline. A statutory claim involves four professionals, and you pay for all of them. Under section 60 of the 1993 Act, the leaseholder is liable for the freeholder's reasonable costs of investigating the right to a new lease, valuing the flat for the premium, and granting the new lease. The 2024 Act repeals section 60, but that repeal too is prospective, listed as a change yet to be applied; on any claim made today, the liability stands.
The verified market ranges for the full stack:
| Fee line | Typical range | Who bears it |
|---|---|---|
| Your solicitor | £800 to £1,300 | You |
| Your valuer | £600 to £900 | You |
| Freeholder's solicitor | £600 to £1,300 | You, under section 60 |
| Freeholder's valuer | £600 to £900 | You, under section 60 |
| Disbursements and HM Land Registry registration | £150 to £300 | You |
Budget £2,750 to £4,700 for the stack as a whole, excluding VAT and any valuer negotiation time. Two adjustments turn that into a real cheque. Professional fees are usually quoted before VAT, so add 20% to the four professional lines when you compare quotes. And if the freeholder's valuer counters high, your valuer bills the negotiation hourly, commonly £150 to £200 an hour. Add both and the same stack becomes roughly £3,600 to £6,600, which is the VAT-inclusive basis used in our guide to what a lease extension solicitor does.
The registration fee itself is the smallest line on the statement. Registering a new lease granted for a premium is assessed on HM Land Registry Scale 1 on the premium plus rent, which is £45 for every premium in the examples above, because they all fall inside the Scale 1 band running up to £80,000. The rest of that £150 to £300 line is official copies of the two titles, notices to lenders and similar disbursements.
On the section 60 side, your exposure is capped twice over: the costs must be reasonable, judged by what a freeholder paying out of their own pocket might expect to incur, and the freeholder's costs of tribunal proceedings over a disputed premium are excluded altogether. The anatomy of both limits, and how a solicitor challenges a padded demand, sits in the solicitor guide linked above.
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Typical costs by unexpired term: the band table
The table below shows how the pieces combine for a flat worth around £300,000 with a modest fixed ground rent. The premium ranges are illustrative, built from the Schedule 13 components at the 5% deferment rate and anchored to published market examples; your own flat's value, ground rent schedule and location will move them. The all-in column adds the £2,750 to £4,700 fee stack, before VAT.
| Unexpired term | Illustrative premium | Marriage value applies? | Illustrative all-in with fees | Main cost driver |
|---|---|---|---|---|
| 95+ years | £3,000 to £5,500 | No | £5,750 to £10,200 | Ground rent capitalisation; reversion still small |
| 90 to 95 years | £4,000 to £6,500 | No | £6,750 to £11,200 | Reversion growing as the term shortens |
| 85 to 90 years | £5,000 to £8,000 | No | £7,750 to £12,700 | Reversion |
| Just over 80 to 85 years | £6,500 to £10,000 | No, but the exemption is lost at exactly 80 years; serve your notice before the term reaches 80 | £9,250 to £14,700 | Reversion; timing risk at the boundary |
| 70 to 79 years | £12,000 to £18,000 | Yes | £14,750 to £22,700 | Marriage value |
| Under 70 years | £18,000 to £40,000+ | Yes, rising steeply | £20,750 to £44,700+ | Marriage value and a fast-approaching reversion |
The cheapest extension you will ever buy is the one you complete while the lease is longest, and the sharpest single saving available to anyone in the 80-to-85 band is serving the notice before the term reaches 80.
One route is missing from the table because it cannot be tabled. An informal extension is agreed directly with the freeholder instead of claimed under the 1993 Act, so it is negotiated rather than calculated: your legal bill is smaller and you pay no section 60 costs, but the freeholder sets the price, sets the added term, can keep or raise the ground rent, and can walk away the day before completion. Price any informal offer against the Schedule 13 figure before you accept it.
The tax treatment: not deductible, but never wasted
Everything above, premium and fee stack alike, is capital expenditure.
No deduction against rental income. If you let the flat, you cannot set the premium or the professional fees against your rents in the year you pay them. The dividing line is the one HMRC draws in its property income guidance: recurring ground rent you pay out is a revenue expense and deductible (see PIM2205, and our page on ground rent rules for the ground-rent side), but the one-off cost of acquiring a longer lease is capital. No amount of creative categorisation changes that.
It enters your CGT base cost. The premium and the associated fees are expenditure on your lease, and they count in the capital gains computation when you eventually sell, alongside what you originally paid for the flat. The authority is section 38 of the Taxation of Chargeable Gains Act 1992, which allows expenditure on the asset reflected in its state at disposal, together with the incidental costs of incurring it. After an extension your lease will comfortably have more than 50 years left to run, so the expenditure counts in full; the wasting-asset restriction that HMRC sets out at CG71141 only bites on leases with fewer than 50 years remaining, which is the opposite end of the problem. The extension itself costs you nothing in CGT, because you are paying money out rather than receiving it, so there is no disposal by you at that point.
Company-held flats get the corporation tax version. Nadia's SPV holds a £450,000 flat with 72 years unexpired and £200 a year of ground rent. At the same rates used above, the term component is around £2,800, the reversion around £13,400, and marriage value is now firmly in play: on relativity in the high 80s to low 90s the uplift runs to roughly £25,000 to £37,000, of which the freeholder takes half. That puts the premium near £29,000, and somewhere between £28,000 and £35,000 across the spread of the published relativity graphs, plus roughly £4,400 of fees once VAT is added to the midpoint of the stack above. The company gets no corporation tax deduction against its rental profits for any of it, but the full spend goes into the company's base cost for the flat, reducing the chargeable gain on a future sale.
Watch where the premium sits relative to £40,000. Nadia's premium falls below that line, so no land transaction return is triggered. Move one variable and it does: the same flat with 60 years left rather than 72 has a reversion of around £24,100 and a marriage-value share of around £20,300, which takes the premium to roughly £47,000. At £40,000 or more a return is due and SDLT can follow, including the 5% surcharge that applies to company purchasers. Our surrender and regrant guide works that mechanic in full.
Keep the paperwork for decades. The completion statement, the section 42 notice, the valuation report and every fee invoice are the evidence for a base-cost claim you might not make until the 2040s or 2050s. File them with the lease and treat them as permanent records. A £15,000 premium you cannot evidence at disposal is, at residential CGT rates, potentially £3,600 of tax paid for want of a PDF.
Houses, waiting for reform, and the SDLT question
Houses run on a different statute. A leasehold house falls under the Leasehold Reform Act 1967. The 1967 Act extension adds 50 years at a modern ground rent, a materially worse product than the flat regime's 90 years at a peppercorn, which is why most qualifying house leaseholders skip the extension entirely and buy the freehold under the 1967 Act, with the price assessed under its section 9 valuation. If you own a leasehold house, price enfranchisement first.
Should you wait for the reforms? In cost terms the question answers itself: every month of delay adds reversion value to your premium, and a lease near the 80-year line can cross it while you wait, whereas the saving is unpriceable until the prescribed rates are set. The band-by-band decision framework belongs with the commencement ledger, and it is worked through on the in-force page linked above.
SDLT in one paragraph. A statutory lease extension is treated for SDLT as a surrender of your old lease and the grant of a new one, and where the premium reaches £40,000 or more a land transaction return and SDLT can follow, including the 5% additional dwellings surcharge for owners of other residential property and for companies. Most owner-occupier extensions with premiums in the single thousands are untouched. The full treatment is in our surrender and regrant guide, the rates comparison is in our SDLT on lease extensions vs fresh purchases page, and you can sanity-check a figure with our stamp duty calculator.
Getting to a real number
The ranges on this page will put you within sight of your cost, but only two documents turn sight into certainty: a specialist valuation of your own flat, which fixes the realistic premium range and your negotiating position, and itemised fee quotes for the stack. If your lease is anywhere between 80 and 85 years, treat the valuation as urgent rather than routine, because the section 42 notice date is what freezes the marriage-value position. And before you pay, have a property tax specialist or your accountant confirm how the spend sits in your records: capital rather than revenue, into the base cost, completion statement filed where you will find it in twenty years. The premium buys you 90 years; ten minutes of record-keeping makes sure the tax system gives some of it back when you sell.