SDLT Linked Transactions: Buying Extra Land or a Garden Plot in 2026

What Are Linked Transactions?

HMRC's Stamp Duty Land Tax rules treat two or more property transactions as "linked" when they form part of a single arrangement or scheme between the same buyer and the same seller (or people connected to them, such as family members or companies under common control). The most common real-world scenario is buying a house and then, shortly afterwards, buying an adjoining garden plot, paddock or parking space from the same seller — often because the seller retained a piece of land at the point of the original sale, intending to sell it on separately.

The purpose of the rule is straightforward: without it, a seller and buyer could artificially split a single high-value sale into several smaller "purchases," each priced to fall within a lower SDLT band, to reduce the overall tax bill. Linking closes that loophole by taxing the combined consideration as if it were one transaction.

Worked Example: Buying a House Then a Garden Strip

Imagine a buyer purchases a house for £320,000 from a seller who also owns an adjoining paddock. Six months later, the same buyer purchases the paddock from the same seller for £60,000.

If treated as separate transactions:

• House at £320,000: SDLT of £9,500 (0% to £125,000, 2% on £125,000-£250,000 = £2,500, 5% on £250,000-£320,000 = £3,500 — total £6,000 for a standard-rate purchase; figures vary with first-time buyer or surcharge status)
• Paddock at £60,000: £0 SDLT (below the £125,000 nil-rate threshold)

If linked (which HMRC is likely to conclude, given the same buyer, same seller and the connected timing):

• Combined consideration: £380,000, assessed as a single purchase
• SDLT is calculated on the full £380,000 using the standard bands, which produces a higher total bill than the sum of the two "separate" calculations above, because more of the combined price falls into the higher-rate bands

This is why buyers planning to purchase adjoining land from the same seller — whether immediately or at a later date already agreed in principle — should assume the transactions will be linked and budget for SDLT on the combined price from the outset.

When Transactions Are NOT Linked

The linking rules require a connection between the transactions — not merely proximity in time. Buying an adjoining garden plot from a different, unconnected seller, even a few weeks after completing your house purchase, is not automatically linked, because the "same seller" (or connected seller) requirement is not met. Genuinely separate, independently negotiated purchases — where there was no prior arrangement or understanding connecting the two sales — are also less likely to be treated as linked, even from the same seller, though HMRC will look at the substance of the arrangement rather than just the paperwork.

Why This Matters for Buyers

Linked transaction rules most commonly catch:

• Buyers purchasing a house with a plan (formal or informal) to buy an adjoining plot from the same seller later
• Buyers acquiring a property in stages from a developer who retains adjoining land or a garage/parking space to sell separately
• Family or connected-company transactions structured across multiple smaller "purchases" from the same effective seller

Anyone in one of these situations should get advice from a conveyancing solicitor before agreeing a staged purchase, since the SDLT liability on the combined transaction can be substantially higher than the sum of what each stage would cost if it were genuinely a standalone deal — and getting the SDLT return wrong (or filing separate returns when HMRC would treat the deals as linked) can lead to a later HMRC enquiry, additional tax and interest.