How much SDLT do you pay when buying a new main home if you already own a buy-to-let?

Introduction

A common Stamp Duty Land Tax (SDLT) question is whether buying a new main residence triggers the higher rates when the buyer already owns another dwelling, such as a buy-to-let. People also often ask whether they can reclaim the extra SDLT later if they sell their old home.

The answer depends on the order of events, who owns the other property, and whether the purchase counts as replacing a main residence under the SDLT rules. If a buy-to-let remains in personal ownership, that can still affect the SDLT position even where the buyer is moving from one home to another.

The Question

A homeowner has lived in their current main residence for many years and also owns a separate buy-to-let property with their spouse. They want to sell their current home and buy a more expensive replacement home to live in as their new main residence. They want to know:

• how much SDLT would be payable on the new purchase;
• whether the higher rates for additional dwellings apply because of the buy-to-let; and
• whether any extra SDLT could be reclaimed after selling the old main residence.

The further point raised is whether transferring the buy-to-let into a limited company before the new purchase would change the SDLT result, and what SDLT might arise on that transfer.

Nick’s Explanation

Nick’s core point was that if the buy-to-let is owned personally, the higher rates may apply unless the transaction falls within the replacement of only or main residence rules.

In anonymised form, his explanation was:

“If the buy-to-let property is in personal ownership, you may be subject to higher rates of stamp duty. If that property is disposed of before buying the new main residence, the additional rates would not apply. Disposing of it could mean selling it or transferring it to a limited company, although a transfer to a company may itself create SDLT.”

He also gave indicative figures based on the numbers provided:

• standard residential SDLT on a purchase at £370,000: £8,500;
• higher rates residential SDLT on a purchase at £370,000: £27,000.

When asked about transferring the buy-to-let to a company with a market value of about £130,000, Nick indicated that the SDLT on that transfer would be lower, giving an approximate SDLT figure of £6,600, plus legal costs.

The Law

SDLT on residential property is charged under the Finance Act 2003. The higher rates for additional dwellings are mainly found in Schedule 4ZA to the Finance Act 2003.

In broad terms, the higher rates can apply where, at the end of the day of purchase:

• the buyer owns an interest in another dwelling worth £40,000 or more; and
• the new purchase is not a replacement of the buyer’s only or main residence.

The replacement of main residence rules are crucial. A buyer can avoid the higher rates on a new home purchase if, broadly:

• they are buying a dwelling intended to be their only or main residence; and
• they have disposed of a previous only or main residence within the permitted period.

If the new home is bought before the old main residence is sold, the higher rates may be payable first, but a refund may later be available if the old main residence is sold within the statutory time limit and the other conditions are met.

Owning a buy-to-let does not automatically mean the higher rates must apply. The key question is whether the purchase is treated as replacing a main residence. If it is, the higher rates can be switched off even though another dwelling is still owned.

Where a personally owned dwelling is transferred to a company connected with the owners, SDLT is usually calculated by reference to market value rather than any lower actual consideration. If there is an outstanding mortgage, debt assumption can also matter. There can also be Capital Gains Tax and financing consequences, though those are separate from SDLT.

Analysis

Using the figures given, the practical SDLT analysis works like this.

First, if the buyer sells the current main residence before buying the new home, and the new home is bought as the replacement main residence, the transaction will usually fall within the replacement exception. In that case, the standard residential SDLT rates apply.

On a purchase price of £370,000, the standard SDLT figure stated by Nick was £8,500.

Secondly, if the buyer purchases the new main residence before selling the old one, they will usually own:

• the old main residence;
• the buy-to-let; and
• the new property.

In that situation, the higher rates often apply on completion because the old main residence has not yet been disposed of. On the figures given, Nick calculated the higher-rates SDLT at £27,000.

If the old main residence is then sold within the refund window and the statutory conditions are met, the buyer can generally reclaim the additional SDLT element attributable to the higher rates.

Thirdly, if the old main residence is sold before the new purchase, the existence of the buy-to-let does not necessarily prevent the replacement exception from applying. This is the point many buyers miss. The legislation asks whether the buyer is replacing a main residence, not whether they own any other property at all. If the former main residence has been disposed of in time and the new property becomes the new main residence, standard rates may still apply.

Fourthly, transferring the buy-to-let to a limited company before buying the new home may remove that dwelling from personal ownership, but this is not a simple workaround. A transfer to a company is itself a separate land transaction. SDLT can arise on the company acquisition, often on market value rules if the company is connected. On the facts provided, Nick gave an approximate SDLT figure of £6,600 on a transfer value of around £130,000, plus conveyancing costs.

That means the buyer should not assume that incorporation is cost-free. It may also involve:

• legal fees;
• Land Registry formalities;
• possible mortgage consent or refinance issues;
• Capital Gains Tax issues; and
• income tax and company extraction considerations.

Finally, the refund question depends on which property is sold. Selling the old main residence can support a refund claim if the new purchase was made first and the higher rates were paid on that basis. Selling or transferring the buy-to-let is a different matter. That may change future ownership status, but it is not the usual refund route where the buyer is replacing their home.

Outcome

The practical conclusion is:

• if the current main residence is sold before the new main residence is bought, SDLT is likely to be charged at standard residential rates, which on the figures provided is £8,500;
• if the new main residence is bought before the current one is sold, higher rates may be payable upfront, which on the figures provided is £27,000;
• if the old main residence is then sold within the statutory time limit and the conditions are met, a refund of the additional SDLT may be available;
• transferring the buy-to-let to a limited company may itself trigger SDLT and other taxes, so it should not be done without full advice.

Practical Steps

To assess the correct SDLT position, a buyer should work through these points in order:

1. Confirm who owns each property, including whether the buy-to-let is owned personally, jointly, or through a company.
2. Identify the intended sequence: sale of the old home first, or purchase of the new home first.
3. Check whether the current home is clearly the only or main residence for SDLT purposes.
4. Calculate SDLT on both bases: standard rates and higher rates.
5. If buying before selling, diarise the deadline for any refund claim after the old main residence is sold.
6. If considering a transfer of the buy-to-let to a company, obtain advice not just on SDLT but also on Capital Gains Tax, mortgage consequences, and legal costs.
7. Keep evidence showing occupation history and sale/purchase dates in case HMRC asks for support for the main residence replacement treatment.

Conclusion

Owning a buy-to-let does not automatically mean higher SDLT must be paid on a replacement home. The key issue is whether the purchase qualifies as replacing an only or main residence. If the old home is sold before the new one is bought, standard rates will often apply. If the new home is bought first, higher rates may be due initially, but a refund may be available once the old main residence is sold in time.

Legal References Used

• Finance Act 2003
• Finance Act 2003, Schedule 4ZA
• HMRC guidance on higher rates for additional dwellings

This page was last updated on 22 March 2026.

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