Guidance on Land Transaction Tax and Stamp Duty Land Tax Rules

Linking SDLT and LTT Transactions Around 1 April 2018

From 1 April 2018, Land Transaction Tax replaced Stamp Duty Land Tax for most Welsh land transactions, but transactions taxed under different regimes cannot be linked with each other. The main issue is to work out first whether each transaction falls under SDLT or LTT, including whether special transitional rules keep a post-1 April 2018 Welsh transaction within SDLT.

• An LTT transaction cannot be linked with an SDLT transaction, even if the deals are connected, involve the same parties, or were negotiated together.
• A Welsh transaction completing on or after 1 April 2018 will usually fall under LTT, unless Wales Act transitional rules keep it within SDLT.
• A delayed completion date alone does not automatically count as a contract variation that removes transitional SDLT treatment.
• Some leases and substantially performed lease arrangements can remain within SDLT after 1 April 2018, while later or successive leases may fall into LTT.
• If land is partly in Wales and partly in England or Northern Ireland, the price must be split on a just and reasonable basis between the relevant tax regimes.
• In practice, you should identify the land, the effective date, and any transitional rules first, and only then consider linked transaction rules within the same tax system.

Scroll down for the full analysis.

When SDLT and LTT transactions can and cannot be linked across 1 April 2018

This page explains how the change from Stamp Duty Land Tax to Land Transaction Tax in Wales affects linked transactions and transitional cases. The key point is that, from 1 April 2018, a Welsh land transaction may fall into LTT rather than SDLT, but that does not mean transactions on either side of the changeover can be grouped together. Whether a transaction is taxed under SDLT or LTT depends on the land involved, the effective date, and in some cases special transitional rules.

What this rule is about

Before 1 April 2018, SDLT applied to land transactions in Wales as well as in England and Northern Ireland. From 1 April 2018, LTT replaced SDLT for transactions relating to land in Wales. SDLT continued to apply in England and Northern Ireland.

This creates two practical questions:

• Can a post-1 April 2018 LTT transaction be linked with an earlier SDLT transaction?
• What happens where a contract was made before 1 April 2018, but completion or another tax trigger happens later?

The official material deals with both points. It confirms a strict separation between post-1 April 2018 LTT transactions and pre-1 April 2018 SDLT transactions, while also recognising that some pre-2018 contracts remain within SDLT because of transitional rules.

What the official source says

The official position is that transactions subject to LTT and occurring after 1 April 2018 cannot be linked to transactions that occurred before 1 April 2018 and were subject to SDLT.

This applies even if the transactions are commercially connected, negotiated together, or involve the same buyer and seller group. The examples show that:

• a Welsh acquisition completed on or after 1 April 2018 may be chargeable to LTT, while an English acquisition completed at the same time is chargeable to SDLT, and the two are not linked with each other for either tax;
• an earlier Welsh acquisition completed before 1 April 2018 and taxed under SDLT cannot be linked with a later Welsh acquisition completed on or after 1 April 2018 and taxed under LTT.

The source also explains that some transactions with an effective date on or after 1 April 2018 still remain within SDLT because of transitional rules in section 16(5) and (6) of the Wales Act 2014. In particular:

• if a contract was not entered into on or before 17 December 2014, those transitional rules do not apply, so a Welsh transaction completing on or after 1 April 2018 falls into LTT;
• if a contract was entered into before that date and the statutory conditions are met, the transaction may remain chargeable to SDLT even though completion happens after 1 April 2018;
• a delayed completion date, by itself, is not necessarily treated as a variation of contract that would take the transaction out of the transitional rules;
• special rules also apply to certain leases treated as arising by substantial performance before Royal Assent to the Wales Act, with SDLT continuing to apply to that deemed lease, while later granted leases or successive leases after 1 April 2018 may fall into LTT.

The source further notes that where a transaction relates partly to land in Wales and partly to land in England or Northern Ireland, the relevant consideration must be apportioned on a just and reasonable basis.

What this means in practice

The change to LTT did not create one combined system across the border or across time. In practice, you must identify which tax applies to each transaction first. Only then can you consider whether transactions are linked within that tax regime.

If one transaction is taxed under SDLT and another under LTT, they are not linked with each other for SDLT or LTT purposes simply because they are connected in a commercial sense.

This matters because linked transaction rules can affect how tax is calculated. If transactions are not linkable across the SDLT/LTT divide, each regime looks only at the transactions falling within its own scope.

The examples also show that the date of completion is not the whole story. A transaction completing after 1 April 2018 may still be taxed under SDLT if it falls within the Wales Act transitional rules. So the practical analysis is not just “before or after 1 April 2018”, but also “does a transitional SDLT rule keep this transaction in the old system?”

For conveyancers and taxpayers, that means returns may need to be made to different authorities for related acquisitions:

• HMRC for SDLT transactions;
• the Welsh Revenue Authority for LTT transactions.

How to analyse it

A sensible way to approach these cases is to work through the following questions in order.

• What land is being acquired? If the land is in Wales, LTT may apply from 1 April 2018. If it is in England or Northern Ireland, SDLT continues to apply.
• What is the effective date of the transaction? This is central, but it is not always the end of the analysis.
• Does the transaction remain subject to SDLT because of the Wales Act transitional rules? The source specifically points to section 16(5) and (6).
• If the contract was entered into before the relevant cut-off, has anything happened that might prevent the transitional rules from applying, such as a relevant variation? The source makes clear that a delayed completion date does not automatically amount to such a variation.
• Are you dealing with a lease that was treated as granted by substantial performance before the Wales Act received Royal Assent? If so, SDLT may continue to apply to that deemed lease even after 1 April 2018.
• Once the correct tax is identified, ask whether there are other transactions within that same tax regime that may be linked. Do not try to link an SDLT transaction with an LTT transaction.
• If the transaction includes land in more than one jurisdiction, apportion the consideration on a just and reasonable basis.

The source also makes an important interpretive point. References to a transaction with an effective date before 1 April 2018 include transactions that remain subject to SDLT under the transitional rules, even if their actual effective date is later. Conversely, references to transactions with an effective date on or after 1 April 2018 exclude those transitional SDLT cases.

Example

A buyer agrees to acquire two Welsh properties from the same seller. One completes in March 2018 and is taxed under SDLT. The second completes in April 2018. If the second transaction does not fall within the Wales Act transitional rules, it is taxed under LTT. Even though the properties are in the same country, involve the same parties, and may have been negotiated together, the March SDLT transaction and the April LTT transaction are not linked with each other.

By contrast, if there are two separate Welsh acquisitions both falling within LTT, the usual LTT linked transaction analysis may still be relevant. The official source expressly leaves open that transactions within Wales may be linked with other Welsh transactions in the same regime.

Why this can be difficult in practice

The difficult part is often not the linked transaction rule itself, but deciding which tax regime applies in the first place.

Three areas can cause uncertainty:

• Transitional contracts. A post-1 April 2018 completion is not automatically an LTT case. The date the contract was entered into, and whether the transitional conditions continue to be met, may be critical.
• Variations and delays. The source confirms that a delayed completion date is not, by itself, treated as a variation that disapplies the transitional rules. But in other factual situations, changes to the contract may need careful analysis.
• Leases and substantial performance. Lease rules can create deemed grants and continuing SDLT consequences even after 1 April 2018, while later granted or successive leases may move into LTT. That can make the timeline hard to follow.

Cross-border transactions also need care. If a deal includes land in Wales and land in England or Northern Ireland, the tax position may need to be split between LTT and SDLT, with the price apportioned on a just and reasonable basis. That is a separate issue from linking, but it often arises in the same transactions.

Key takeaways

• A transaction subject to LTT after 1 April 2018 cannot be linked with a transaction that was subject to SDLT before that date.
• Some transactions completing on or after 1 April 2018 still remain within SDLT because of the Wales Act transitional rules.
• The first step is always to identify the correct tax regime for each transaction before considering whether any transactions can be linked within that regime.

This page was last updated on 24 March 2026

Useful article? You may find it helpful to read the original guidance here: Guidance on Land Transaction Tax and Stamp Duty Land Tax Rules

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