Stamp Duty on Staircasing Shared Ownership to 100%
NO VAT
How is SDLT calculated when staircasing a shared ownership property to 100%?
Introduction
People often ask how Stamp Duty Land Tax (SDLT) works when they increase their share in a shared ownership home. The question usually arises when a buyer originally paid SDLT only on the first share they bought, and later decides to staircase to 100% ownership. A common point of confusion is whether SDLT is worked out by reference to the whole current market value of the property on a pro-rata basis, or by reference to the actual amount paid for the extra share.
This matters because the method used can change the SDLT bill. It also matters whether the buyer made a market value election when they first bought the shared ownership lease, and whether First-Time Buyers’ Relief was claimed at that stage.
The Question
A buyer and their partner bought a 30% share in a shared ownership home in 2021. They paid SDLT only on that initial share and did not elect to pay SDLT on the full market value of the property at the outset. They are now staircasing to 100% by buying the remaining 70% for £266,000.
The conveyancer calculated SDLT by taking the price for the additional share, dividing it by the current full market value of the property, and applying that proportion to the SDLT that would have been due on the whole property value. That produced a figure of £2,800.
The buyer wanted to know whether that method is correct, and whether a previous claim to First-Time Buyers’ Relief changes the result.
Nick’s Explanation
Nick’s view was that the staircasing transaction becomes chargeable because the acquisition takes the buyers above the 80% threshold. He explained that where no market value election was made on the original purchase, a later staircasing transaction beyond 80% is not exempt and SDLT is charged on the actual consideration paid for the additional share.
In anonymised form, his reasoning was:
Because the buyers did not elect to pay SDLT on the full market value when they first acquired the shared ownership lease, the later staircasing transaction is tested under Schedule 9 to the Finance Act 2003. Once the staircasing takes total ownership above 80%, the exemption no longer applies. SDLT is then charged on the chargeable consideration actually given for the additional share.
He also rejected the conveyancer’s pro-rata calculation:
The legislation does not provide for SDLT to be calculated by taking the proportion of the share acquired against the current market value of the whole property and then applying that proportion to a hypothetical SDLT figure on the whole value. The tax is charged on the actual amount paid for the staircasing acquisition.
On the figures given, Nick said the SDLT should be calculated on £266,000 using the ordinary residential rates that applied to that transaction, producing:
- 0% on the first £125,000 = £0
- 2% on the next £125,000 = £2,500
- 5% on the remaining £16,000 = £800
- Total SDLT = £3,300
He also said that a previous claim to First-Time Buyers’ Relief does not change the SDLT treatment of the later staircasing transaction. In his words, again anonymised:
First-Time Buyers’ Relief is only relevant on the initial purchase and does not apply to a later staircasing transaction of this kind. The later acquisition is taxed under the shared ownership rules in Schedule 9, and the SDLT is worked out on the actual consideration paid for that later share.
The Law
The relevant rules are in Schedule 9 to the Finance Act 2003, which deals with shared ownership leases for SDLT purposes.
In broad terms, a buyer of a shared ownership lease can either:
- pay SDLT in stages, meaning tax is considered as further shares are acquired, or
- make a market value election and pay SDLT upfront on the full market value at the time of the first purchase.
If no market value election is made, later staircasing transactions are considered under the special rules in Schedule 9.
Paragraph 4A(1)(b) defines a staircasing transaction as an acquisition of an additional interest, calculated by reference to the market value of the dwelling and expressed as a percentage of the dwelling or its value.
Paragraph 4A(2)(b) provides an exemption where, immediately after the acquisition, the total share held by the lessee or lessees does not exceed 80%.
The effect is that staircasing transactions up to and including 80% may be exempt, but once the acquisition takes the buyer above 80%, the exemption no longer applies.
Where the exemption does not apply, SDLT is charged by reference to the chargeable consideration for the transaction. In a straightforward staircasing case, that is the amount actually paid for the additional share being acquired.
As for First-Time Buyers’ Relief, that relief is governed by separate provisions in the Finance Act 2003. It can apply to an initial qualifying purchase, but it does not carry forward to later staircasing purchases as a separate relief on those later transactions.
Analysis
The analysis can be broken down into four steps.
Identify whether a market value election was made on the original shared ownership purchase.
Here, the buyer paid SDLT only by reference to the initial 30% share and did not elect for market value treatment. That means the later staircasing must be considered under the staged rules in Schedule 9.
Check whether the later acquisition remains within the 80% exemption.
The buyers are increasing their holding from 30% to 100%. Immediately after the acquisition, they will hold more than 80%. So the exemption in paragraph 4A(2)(b) is not available.
Work out what amount is chargeable.
The relevant transaction is the purchase of the extra 70% share for £266,000. The legislation does not say that the tax should be computed by reference to a fraction of the current whole market value and then matched to a hypothetical whole-property SDLT figure. Instead, the chargeable consideration is the actual amount paid for the additional interest.
Apply the ordinary residential SDLT rates to that amount.
Using the figures provided and the rate bands stated in Nick’s explanation, SDLT on £266,000 comes to £3,300.
That is why the pro-rata figure of £2,800 is difficult to support from the wording of Schedule 9.
The First-Time Buyers’ Relief point does not alter this conclusion. If relief was relevant on the original acquisition, that does not mean it applies again when a later staircasing transaction is taxed. The later transaction stands on its own under the shared ownership rules.
Outcome
On the facts described, the later staircasing to 100% is an SDLT-chargeable transaction because it takes the buyers above 80% ownership and no market value election was made at the outset.
The better view is that SDLT should be calculated on the actual consideration paid for the additional 70% share, not by using a pro-rata fraction of the whole current market value. On the figures given, that produces SDLT of £3,300 rather than £2,800.
A previous claim to First-Time Buyers’ Relief does not reduce the SDLT due on that later staircasing transaction.
Practical Steps
If you are checking your own position, it helps to work through the following points:
- Find the original shared ownership lease and SDLT return.
- Check whether a market value election was made on the original purchase.
- Confirm your ownership percentage before and after the staircasing transaction.
- Identify the actual price being paid for the additional share.
- Check which residential SDLT rates applied on the effective date of that staircasing transaction.
- Do not assume that a pro-rata calculation based on the whole property value is correct unless there is a clear legislative basis for it.
- Do not assume that First-Time Buyers’ Relief can be used again on a later staircasing purchase.
- Ask your conveyancer or tax adviser to explain exactly which statutory provision supports the method used.
If there is a disagreement about the calculation, the key documents are usually the original lease, the original SDLT filing position, the staircasing memorandum, and the valuation or pricing documents for the additional share.
Conclusion
Where a shared ownership buyer did not elect to pay SDLT on full market value at the start, a later staircasing transaction beyond 80% is generally chargeable to SDLT. The tax is ordinarily calculated on the amount actually paid for the extra share, using the normal residential rates, and not by a pro-rata formula based on the whole current value of the property. A previous First-Time Buyers’ Relief claim does not change that result.
Legal References Used
- Finance Act 2003, Schedule 9
- Finance Act 2003, Schedule 9, paragraph 4A(1)(b)
- Finance Act 2003, Schedule 9, paragraph 4A(2)(b)
- Finance Act 2003 provisions governing First-Time Buyers’ Relief
This page was last updated on 22 March 2026.
See all questions and answers categorized in this sitemap. Or use Google site search below.
