SDLT When Transferring Property to a Limited Company: Traps and Partnership Relief

Section 162 incorporation relief is a capital gains tax mechanism. It does nothing for Stamp Duty Land Tax, and SDLT is often the larger cash bill on a portfolio incorporation. Landlords who focus entirely on the CGT deferral and forget the SDLT side find a six-figure tax due 14 days after completion on a transfer they thought of as moving assets between their own pockets. This piece sits under the pillar guide on the new 2026 Section 162 claims process, and pairs with the companion pieces on handling existing mortgages on incorporation and portfolio valuation and HMRC dispute risk.

The SDLT analysis turns on three rules that catch landlords out: connected-party transfers happen at market value regardless of cash consideration, the additional-dwelling surcharge applies whenever a company acquires a residential dwelling, and the partnership relief in Schedule 15 of the Finance Act 2003 is the only common route around the charge. Each is set out below with the practical implications for a Harrow portfolio.

Why SDLT is charged at market value

A landlord transferring property to their own limited company is dealing with a connected person. The SDLT rules treat connected-party transfers as taking place for a chargeable consideration equal to the market value of the property, regardless of what is actually paid. So even where the company issues shares as consideration, or assumes a mortgage, or both, the SDLT is computed on the full market value of each dwelling. Leaving the consideration loose, or showing a low cash figure on the transfer, does not reduce the charge. It only invites a later enquiry.

The same rule applies where the consideration is a director loan account balance, share issue, or any combination. SDLT looks through the form to the market value of the thing transferred. Landlords sometimes ask whether a small token consideration can be used to anchor a low SDLT figure; the answer, on a connected-party transfer of a dwelling, is no.

The additional-dwelling surcharge on a company purchase

The 5 percent additional-dwelling surcharge applies whenever a company acquires a residential dwelling in England, regardless of whether the company already owns any other property. The company has no main residence and no equivalent of the individual replacement-of-main-residence relief. Every dwelling transferred into the SPV attracts the surcharge on top of the standard residential rates. For a portfolio of any size this is the dominant SDLT cost.

The numbers above are indicative only. The actual SDLT depends on banding, the precise value of each property, and any reliefs the transaction can support. The point is the scale: the surcharge alone is rarely smaller than a year of net rental income from the portfolio.

Multiple Dwellings Relief has largely been removed

Multiple Dwellings Relief used to allow the SDLT on a transfer of more than one dwelling to be calculated on the average value per dwelling, then multiplied by the number of dwellings, which tended to reduce the total. The relief was significantly curtailed and is no longer available for the typical landlord incorporation. Planning that relied on MDR to reduce SDLT on a portfolio transfer does not work for transactions in 2026. Treat any older advice that quotes MDR as out of date and reprice the transfer at the standard rates plus the surcharge.

The Schedule 15 partnership route

The most important and the only commonly available SDLT relief on incorporation is the partnership relief in Schedule 15 of the Finance Act 2003. Where the properties are genuinely held and run as a partnership, transferring that partnership business into a limited company can attract a relief that, in straightforward cases, removes most or all of the SDLT charge. The mechanics involve a calculation of sum-of-the-lower-proportions that links each partner's pre-transfer interest to the shares issued by the company. The result, where the partners and the shareholders broadly mirror each other, is a charge that approaches zero.

The catch is what counts as a partnership. HMRC looks for the substance of a real partnership carrying on a property business: a written partnership agreement, joint bank accounts, partnership tax returns, shared decision-making, and the business being operated in common with a view to profit. Spouses who happen to own a couple of rented properties jointly are not, without more, a partnership for these purposes. A partnership stitched together a few weeks before incorporation specifically to grab the relief is extremely vulnerable to challenge. The route works when the partnership genuinely exists and has been operating long enough to be credible.

Lead time for a credible partnership

A common working approach is to establish the partnership at least 12 to 24 months before any planned incorporation, run it properly throughout that period with partnership accounts and tax returns, and only then transfer the business into a company. The lead time mirrors the substance-building work needed for the Section 162 business test, and the two exercises tend to be run together. A landlord who needs both the CGT deferral and the SDLT relief has a strong reason to plan well ahead rather than incorporate at short notice.

Common SDLT traps to avoid

• Assuming Section 162 covers SDLT. It does not. The CGT deferral and the SDLT charge are entirely separate.
• Relying on Multiple Dwellings Relief. It has been substantially removed and should not be assumed available.
• Using a paper partnership formed shortly before transfer to claim Schedule 15 relief. HMRC scrutinises substance.
• Forgetting the 14-day filing and payment deadline. SDLT returns and payment are due within 14 days of completion, not at year-end.
• Overlooking linked-transactions rules where several properties move in connected steps.
• Treating share consideration as if it reduces SDLT. Connected-party transfers are taxed at market value.

Mixed-use and commercial property elements

Where a portfolio includes commercial property as well as residential dwellings, the SDLT analysis splits. Commercial property attracts the non-residential SDLT rates and does not attract the 5 percent surcharge. A genuinely mixed-use portfolio may pay materially less SDLT than a purely residential one, and the categorisation of each property is worth checking carefully. HMRC has been active in challenging mixed-use treatment where the commercial element is small or contrived, so the categorisation needs to be defensible on the facts.

Modelling the SDLT cash cost alongside CGT

The honest way to evaluate an incorporation is to model the SDLT cash cost and the CGT position side by side, before any decision is made. The CGT figure is typically larger in headline terms but is deferred where Section 162 succeeds. The SDLT figure is smaller in headline terms but is due in cash within 14 days. For a borderline business test the SDLT charge is paid either way; only the CGT outcome is at risk. That asymmetry should shape how a landlord weighs the trade-off, and it underlines the importance of getting the valuation right because the same market-value figure drives both charges.

The role of the conveyancer and accountant

Incorporation usually needs a conveyancer or solicitor running the property transfers and registering the company as proprietor, alongside an accountant running the CGT, SDLT, and Schedule 15 analysis. The two roles should align early. A conveyancer who is unfamiliar with portfolio incorporation may treat the SDLT as a routine calculation and miss the partnership-relief route or the linked-transactions rules. The accountant should brief the conveyancer in writing on the SDLT analysis, the partnership-relief claim if applicable, and the valuation evidence the SDLT return will rest on.

When the SDLT cost kills the deal

For smaller portfolios with modest CGT exposure but full residential SDLT, the incorporation maths can fail purely on the SDLT side. A two-property portfolio with a £150,000 latent gain and an SDLT cost of £60,000 to £80,000 on transfer is rarely worth incorporating even where Section 162 would defer the CGT. The recurring corporation tax, dividend tax, and compliance cost of running an SPV needs years of saving to recover the up-front SDLT, and most landlords in this position end up holding the properties personally and managing the Section 24 exposure another way. The SDLT analysis is therefore the gating question, not an afterthought, and should be priced before any other planning is done.

Next in the cluster

Once the SDLT analysis is clear, the next operational hurdles are the mortgages and the valuation evidence. The companion piece on handling existing mortgages when incorporating a buy-to-let portfolio sets out the refinancing mechanics and cost, and the piece on portfolio valuation and HMRC dispute risk covers the valuation work that supports both the CGT and SDLT computations. The pillar guide on the 2026 Section 162 claims process ties it together.