Final Staircasing to 100%: Full Ownership SDLT
SDLT on the final share purchase to reach full ownership, the leasehold transition, and what changes once you own 100%.
Key Takeaways
- Final staircasing SDLT is calculated on the price paid for the last share only — not accumulated ownership
- This applies only if you used the staircasing election initially; market value election buyers pay zero SDLT on final staircase
- The final share price is based on a RICS valuation of the full property at the time of the final staircase
- Transitioning from leasehold to freehold is a separate process from reaching 100% equity ownership
- Losing housing association protections on rent and service charges after 100% ownership is a real financial consideration
- The 3% additional dwelling surcharge could apply if you own another residential property when you staircase to 100%
- Going directly to 100% from a lower share in one transaction is called final staircasing and eliminates intermediate staircase filings
- Your mortgage lender must be notified of and consent to the final staircasing transaction before it can complete
In this article
What Is Final Staircasing?
Final staircasing is the transaction in which you buy the remaining share of your shared ownership property to reach 100% ownership. Whether you are buying the last 5% or jumping directly from 40% to 100% in one go, the transaction that takes you to full ownership is the final staircase.
This is a significant milestone. After final staircasing you are an outright owner of your home, with no ongoing rent obligation to the housing association for the portion you did not previously own. The mechanics of the transaction are similar to intermediate staircasing, but with additional legal steps because full ownership changes the structure of your property title.
For context on how SDLT applies to earlier staircase purchases before the final one, see the staircasing stamp duty guide. If you made a market value election at your initial share purchase, no SDLT applies to any staircasing transaction — including this final one.
Calculation Method
Final staircasing crosses the 80% cumulative threshold in most cases (assuming you owned less than 80% before). This means the SDLT calculation uses the market value of the final share, not just the price paid. In practice, these should be identical because the price is set by a RICS valuation — but the legal basis is market value rather than consideration where the 80% threshold is involved.
For example: you own 75% and buy the remaining 25% to reach 100%. The property is currently worth £400,000. The final share price is 25% of £400,000 = £100,000. SDLT: 0% on £100,000 (below £125,000 threshold) = £0.
For a higher-value property at the same ownership split: you own 75%, buy the remaining 25% of a £600,000 property. Final share cost: £150,000. SDLT: 0% on £125,000 + 2% on £25,000 = £500.
Leasehold to Freehold Transition
A common misconception is that buying 100% of your shared ownership property automatically means you own the freehold. This is not the case. In shared ownership, you hold a leasehold interest in the property from the outset. Reaching 100% equity means you own all of the lease — but the freehold remains with the housing association or freeholder.
Acquiring the freehold is a separate process called leasehold enfranchisement. For houses, you have a statutory right to buy the freehold under the Leasehold Reform Act. For flats, individual flat owners must usually act collectively with other leaseholders to enfranchise. The right to buy your freehold is governed by the terms of your lease and the relevant legislation, and involves a separate purchase and its own SDLT calculation.
Some shared ownership housing associations will offer the freehold at the same time as the final staircase, but this is not automatic. If freehold enfranchisement is available, the premium paid for the freehold is a separate chargeable consideration, and SDLT is calculated on that premium in addition to the SDLT on the final leasehold share.
Check Your Lease Terms
Your shared ownership lease sets out the terms under which you can acquire the freehold, if at all. Review these terms with your solicitor before proceeding with the final staircase to understand your full path to outright ownership.
Losing Housing Association Protections
Shared ownership comes with certain protections for the shared owner provided by the housing association. These include regulated rent increases on the unowned share (typically RPI-linked), support with major maintenance issues, and in some cases housing management services.
Once you reach 100% equity ownership, the rent obligation to the housing association ceases — which is the main financial benefit of staircasing fully. However, if you remain on a leasehold title, you may still be subject to service charges and ground rent as set out in the lease, and these protections are governed by leasehold legislation rather than housing association policy.
Service charges on leasehold properties can increase significantly once the housing association is no longer involved in managing your ownership. Understanding the future service charge implications is essential financial planning before committing to final staircasing.
Mortgage Considerations
Final staircasing requires your mortgage to be renegotiated or extended to cover the full purchase price of the remaining share. Your existing shared ownership mortgage will be secured against only your current share. To complete the final staircase, you need a mortgage that covers the new purchase or sufficient savings to buy the final share outright.
Most buyers either extend their existing mortgage with the same lender or remortgage with a new lender to release the funds needed for the final share. The new mortgage is secured against the full property value (not just your share) as you will be the sole owner. Mortgage capacity must be assessed by a mortgage broker or advisor before proceeding.
The housing association will confirm in writing that they consent to the final staircasing once a RICS valuation has been carried out. Your solicitor coordinates the mortgage completion and the staircasing completion to occur simultaneously, ensuring funds are transferred and the title is updated on the same day.
Additional Dwelling Surcharge Considerations
The 3% additional dwelling surcharge (ADS) applies to residential property purchases by buyers who already own at least one other residential property on completion. If you own a buy-to-let property or a second home in addition to your shared ownership home, the ADS could apply to the consideration for the final staircase transaction.
For example, buying the final 25% of a £400,000 property (consideration: £100,000) normally incurs zero SDLT. But with the 3% ADS applied: 3% on £100,000 = £3,000 additional SDLT. This can make a material difference to the cost of final staircasing for those with additional properties.
If the shared ownership property being staircased to 100% is your only residence and you sell any other residential property within three years of completing the final staircase, you can apply for a refund of the ADS. This refund process requires a formal claim to HMRC within the three-year window.
Worked Example: Owning 75%, Buying Remaining 25%
Scenario Details
- Current ownership: 75%
- Final share to purchase: 25%
- Original purchase price: £280,000 (3 years ago)
- Current RICS market valuation: £350,000
- Final share consideration: 25% of £350,000 = £87,500
- Buyer status: Standard (not FTB, no other properties)
SDLT Calculation
| Consideration: 25% of £350,000 | £87,500 |
| SDLT: 0% on £87,500 (below £125,000 threshold) | £0 |
| Total SDLT on final staircase | £0 |
Same Scenario with £550,000 Current Market Value
| Consideration: 25% of £550,000 | £137,500 |
| SDLT: 0% on £125,000 | £0 |
| SDLT: 2% on £12,500 (£125,001–£137,500) | £250 |
| Total SDLT on final staircase | £250 |
With Additional Dwelling Surcharge (owner of another property)
| Consideration: 25% of £550,000 | £137,500 |
| Standard SDLT: £250 | £250 |
| 3% ADS on £137,500 | £4,125 |
| Total SDLT with surcharge | £4,375 |
This illustrates how significantly the additional dwelling surcharge affects the cost of final staircasing for buyers who own additional properties.
Timing Your Final Staircase
The timing of your final staircase affects both the price you pay and the SDLT you owe. Property value growth increases the consideration and therefore any SDLT due. If you believe property values in your area will rise significantly, completing the final staircase sooner locks in a lower price and SDLT basis.
Conversely, if your financial situation means you cannot yet afford the final share, there is no deadline by which you must staircase. The housing association lease will include a staircasing right for the duration of the lease — there is no fixed window. You staircase when it is right for you financially.
If you are selling another property around the same time as final staircasing, timing the sale to complete before the staircase can avoid the additional dwelling surcharge, or at minimum creates the conditions for an ADS refund claim later.
Legal Process for Final Staircasing
The legal process for final staircasing involves several steps:
- Instruct a solicitor and notify your mortgage lender. Your solicitor coordinates with the housing association and your lender simultaneously.
- Commission a RICS valuation of the property to establish the current market value for the share price and SDLT basis.
- Receive the housing association's staircasing memorandum setting out the price for the final share and confirming their consent.
- Arrange mortgage finance for the final share if not buying with savings. Your lender will carry out their own valuation.
- Exchange of contracts between you and the housing association (or in some cases a deed of variation to the lease).
- Completion — funds transfer, lease surrendered or amended, SDLT return filed within 14 days.
- Land Registry update to reflect 100% ownership on the title. Your SDLT certificate is required for this.
After You Own 100%
Once the final staircase completes and the title is updated, you are the full equity owner of your home. Your rights and obligations change immediately: there is no more rent to the housing association, you cannot be asked to sell back to the housing association, and you can sell on the open market without restriction.
If you later sell the property, the full sale proceeds are yours. SDLT rules that apply to you as a future seller are the same as for any standard property sale — see the standard purchase guide for how SDLT works from a buyer's perspective on a conventional sale.
The shared ownership journey from initial purchase through to 100% ownership can involve multiple SDLT events. For a comprehensive overview of every touchpoint, revisit the shared ownership complete guide.
Calculate Your Stamp Duty
Use our calculator to work out the exact stamp duty for your property purchase.
Your Results
Stamp Duty to Pay
£5,000
Effective tax rate: 1.67%
Tax Breakdown
| Band | Rate | Tax |
|---|---|---|
| £0 - £125,000 | 0% | £0 |
| £125,001 - £250,000 | 2% | £2,500 |
| £250,001 - £300,000 | 5% | £2,500 |
| Total | £5,000 | |
£0 - £125,000
0%
£0
£125,001 - £250,000
2%
£2,500
£250,001 - £300,000
5%
£2,500
Total
£5,000
Tax by Band
Added to 25-Year Mortgage
£29/month
Based on 5% interest rate, added to loan amount
Frequently Asked Questions
How is stamp duty calculated when I staircase to 100%?
SDLT is calculated on the price you pay for the final remaining share only. If you own 75% and buy the last 25%, SDLT is due on the price of that 25% based on the current RICS valuation. Standard rates apply: 0% up to £125,000, 2% on the next £125,000, and 5% above £250,000 (per band). Most final staircase transactions on moderate-value properties result in zero or minimal SDLT.
Do I get the freehold when I staircase to 100%?
Not automatically. Reaching 100% equity means you own all of the lease, but the freehold may remain with the housing association. For houses, you may have a statutory right to buy the freehold separately under leasehold reform legislation. For flats, freehold enfranchisement usually requires collective action with other leaseholders. Your solicitor can advise on your specific freehold rights.
Can I get the additional dwelling surcharge on final staircasing?
Yes, if you own another residential property on the completion date of the final staircase, the 3% additional dwelling surcharge applies to the consideration. If the staircased property becomes your main residence and you sell any other property within three years, you can claim an ADS refund from HMRC.
Do I need to remortgage when I staircase to 100%?
In most cases yes, unless you can fund the final share from savings. Your existing shared ownership mortgage needs to be extended or replaced to cover the new total mortgage value on full ownership. Your mortgage lender must also formally consent to the staircasing transaction. A mortgage broker or advisor can guide you through the options.
Can I jump directly to 100% from a low share like 40%?
Yes. You can staircase directly from any current percentage to 100% in one transaction. SDLT is calculated on the full remaining share in that single transaction — in this case the 60% balance. This avoids multiple intermediate staircase filings and may be more cost-efficient depending on the property value and individual staircase sizes.
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Emma Richardson, MRICS
Chartered Surveyor & Property Tax Specialist
Emma Richardson is a RICS-qualified Chartered Surveyor with over 12 years of experience in UK property taxation. She founded Stamp Duty Calculator to help buyers understand the complex world of property transaction taxes.