Stamp Duty Refund When You Sold Your Previous Home After Completion

The 5% additional-dwelling surcharge — applied to anyone who already owns a residential property when they complete on a new one — is the largest single item of SDLT refund activity in the UK. The reason is built into the rules: HMRC requires the surcharge to be paid up front based on circumstances at completion, but allows reclaim if the buyer disposes of their previous main residence within 36 months. Many buyers end up paying the surcharge, selling within the window, and reclaiming. The mechanism is well-established and refunds are usually paid without dispute.

The basic mechanics

You own a residential property as your main residence. You complete on a new property to be your main residence, but you have not yet sold the previous one (perhaps because of chain difficulties, or simply because you decided to buy before you sold). At completion, you own two residential properties — so the 5% surcharge applies on the full purchase price of the new property.

You then sell the previous main residence within 36 months of the new completion. On disposal, you have replaced your main residence — and the surcharge is now reclaimable in full. You file an amended SDLT return (or a separate reclaim form, depending on the timing) and HMRC repays the surcharge into your bank account.

What counts as "disposed of"

The previous main residence is "disposed of" on the date of completion of its sale (or transfer for nil consideration). Putting it on the market doesn't count. Accepting an offer doesn't count. Even exchanging contracts doesn't count for these purposes — what matters is the date the conveyance completes.

Other dispositions can qualify too: transferring ownership to a spouse or family member; transferring to a trust; selling to a company; gifting. The legal mechanism doesn't matter as long as the buyer no longer holds the chargeable interest after the disposal.

Typical refund sizes

The surcharge is 5% of the entire purchase price of the new property. So the refund is 5% of that price.

£300,000 new home: refund of £15,000.

£500,000 new home: refund of £25,000.

£750,000 new home: refund of £37,500.

£1,000,000 new home: refund of £50,000.

These are full surcharge refunds — the underlying standard SDLT is not refunded, only the additional-dwelling layer.

Documentation HMRC requires

The reclaim is a fairly mechanical process for HMRC. The key documents are: (1) the completion statement on the new purchase, showing SDLT paid including the surcharge; (2) the SDLT1 reference number; (3) the completion statement on the disposal of the previous main residence; (4) confirmation that the previous property was the buyer's main residence in the period before completing on the new home.

The reclaim is filed using HMRC's online form (an SDLT amendment if within 12 months of the original return, or a separate higher-rate reclaim form if later). Payment is by BACS to the bank account specified in the claim. The typical processing time is six to twelve weeks.

Common reasons claims get held up

The replacement-of-main-residence relief is generally a clean and well-administered reclaim. The most common reasons for delay or rejection are: (1) the previous property was never actually the buyer's main residence (e.g. it had been let out for years before sale); (2) the timing is unclear or the new completion date and old disposal date are wrongly recorded; (3) the new property is being bought through a company (companies cannot have a "main residence" and the relief therefore doesn't apply); (4) the buyer is non-UK-resident and the 2% non-resident surcharge also applies — the rules for reclaiming each surcharge are different and need to be handled separately.