Guide on Calculating SDLT for Linked Leases with Modified Rules

SDLT for linked leases under one arrangement

Where two leases are linked for SDLT but are not treated as successive leases, you do not work out the tax on each lease entirely on its own. Instead, you add the net present value (NPV) of the rent under both leases to find the right SDLT rates and thresholds, then split the resulting tax between the leases in proportion to each lease’s share of the total NPV.

• Each lease still has its own SDLT calculation, but both calculations use the combined NPV of the linked leases for rate and threshold purposes.
• For each lease, you apply the SDLT rules in force on that lease’s grant date, so the result can differ if the leases were granted at different times.
• The tax is then apportioned by NPV, so each lease bears only its proportionate share of the notional tax on the combined rental value.
• The residential or non-residential treatment is decided by looking at all the land covered by both leases together, not each lease separately.
• A linked lease may suffer more SDLT than if viewed alone, because the combined NPV can move the transaction into a higher SDLT band.
• The main practical issues are deciding whether the leases are linked or successive, using the correct grant-date rules, and ensuring the NPV figures are accurate.

Scroll down for the full analysis.

How SDLT is calculated for linked leases under a single scheme

This page explains how SDLT is worked out where two leases are linked, but they are not treated as successive leases under the special rules for successive lease transactions. In that situation, HMRC’s manual says you do not simply tax each lease in isolation. Instead, you look at the rents under both leases together to work out the right SDLT rate structure, and then apportion the resulting tax between the leases.

What this rule is about

SDLT has special rules for linked transactions. The purpose is to stop closely connected transactions being taxed as if they were completely separate when, in substance, they form part of one arrangement.

For leases, this matters because SDLT on rent is based on the net present value, or NPV, of the rent payable over the term. If two leases are linked, the legislation can require the NPVs to be aggregated when applying the SDLT thresholds and rates.

The page you provided deals with a specific situation:

• the leases are linked for SDLT purposes,
• but the special rules for successive leases do not apply,
• so the calculation is modified under Schedule 5 to the Finance Act 2003.

The practical point is that you still calculate a separate SDLT liability for each lease, but each calculation is influenced by the combined rental value of both leases.

What the official source says

HMRC’s manual says that where linked leases are not covered by the successive lease rules, the SDLT calculation is carried out in two stages, once for each lease.

For the first lease:

• calculate the NPV of the first lease,
• add it to the NPV of the second lease,
• treat that combined figure as the relevant rental value,
• apply the SDLT threshold and rates in force at the date the first lease was granted, taking account of whether the combined land is residential or non-residential,
• then apportion that total tax by reference to the fraction: NPV of first lease divided by total NPV.

For the second lease, you repeat the exercise:

• calculate the NPV of the second lease,
• add it to the NPV of the first lease,
• apply the threshold and rates in force at the date the second lease was granted, again based on the status of all the land covered by either lease,
• then apportion that total tax by reference to the fraction: NPV of second lease divided by total NPV.

So the leases are aggregated to determine the appropriate rate structure, but the resulting SDLT is then split proportionately between them.

What this means in practice

The main practical effect is that a lease may bear more SDLT than it would have done if looked at on its own, because the linked lease pushes the combined NPV into a higher charging band or otherwise affects the threshold calculation.

At the same time, the tax is not simply duplicated. You do not charge the full tax on the combined NPV to each lease. Instead, you calculate the tax that would arise if both leases were one transaction, and then allocate that tax between the leases in proportion to their respective NPVs.

This approach is intended to be fair and proportionate. HMRC’s manual expressly says the leases are linked and the NPVs aggregated for threshold and rate purposes, but these are not successive leases, so the separate successive lease provisions do not apply.

Another practical point is timing. Because the first and second lease may be granted on different dates, the SDLT thresholds and rates applied to each calculation may differ. That is why the manual requires two separate tax calculations rather than one single global figure.

The residential or non-residential treatment is also determined by looking at the status of all the relevant land across both leases, not just the land in one lease viewed alone.

How to analyse it

A sensible way to approach this issue is to ask the following questions.

• Are the leases linked for SDLT purposes?
• If they are linked, do the special rules for successive leases apply instead?
• If not, what is the NPV of the rent under each lease?
• What is the combined NPV of both leases?
• What SDLT rates and thresholds applied on the date each lease was granted?
• Is the total relevant land, taken as a whole, residential or non-residential for these purposes?
• Once the notional total tax is calculated for each lease date, what proportion should be allocated to each lease by reference to its share of the total NPV?

This structure matters because there are really two separate tasks:

• first, identify the combined rental value so the correct SDLT charging framework is used;
• second, apportion the resulting tax so that each lease bears only its proper share.

The source material is specifically about the rent element of lease consideration, using NPV. It does not say that the leases are merged into one actual lease for all SDLT purposes. The aggregation is used to apply the rates and thresholds correctly under the linked transaction rules.

Example

This is an illustration of the method described in the HMRC manual.

Assume two leases are linked, neither is treated under the successive lease rules, and the NPV of the rent is:

• Lease 1: NPV1 = £200,000
• Lease 2: NPV2 = £300,000

The total NPV is therefore £500,000.

For Lease 1, you calculate the SDLT that would have been due if a single lease with an NPV of £500,000 had been granted on the date Lease 1 was granted. You then allocate to Lease 1 the proportion 200,000 / 500,000 of that tax.

For Lease 2, you again use the total NPV of £500,000, but this time apply the SDLT thresholds and rates in force on the date Lease 2 was granted. You then allocate to Lease 2 the proportion 300,000 / 500,000 of that tax.

If the SDLT rules changed between the two grant dates, the tax figure used for Lease 1 and Lease 2 may not be the same, even though the total NPV is the same in both calculations.

Why this can be difficult in practice

The first difficulty is deciding whether the leases are merely linked, or whether they fall within the separate rules for successive leases. The calculation method is different, so classification matters.

The second difficulty is that two different grant dates can mean two different SDLT charging regimes. That makes the calculation less intuitive than simply adding the rents together once.

The third difficulty is the status of the land. The manual says the residential or non-residential threshold depends on the status of all the land which is the subject of either lease. In mixed or unusual property arrangements, that may require careful analysis.

There can also be practical uncertainty where the transactions are commercially connected but the legal and factual basis for treating them as linked is not straightforward. The source material assumes that the leases are linked; it does not set out the full test for linkage.

Finally, because the calculation uses proportional apportionment by NPV, errors in the NPV figures will affect both lease calculations.

Key takeaways

• Where leases are linked but not successive, SDLT on rent is calculated by aggregating the NPVs to determine the applicable thresholds and rates.
• You still calculate a separate SDLT amount for each lease, using the rates in force on that lease’s grant date, and then apportion tax by reference to that lease’s share of the total NPV.
• The status of all the land covered by the linked leases matters when deciding whether the residential or non-residential charging rules apply.

This page was last updated on 24 March 2026

Useful article? You may find it helpful to read the original guidance here: Guide on Calculating SDLT for Linked Leases with Modified Rules

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