Manual Calculation Example of Net Present Value for Ten-Year Lease Rent

How SDLT calculates the net present value of lease rent

For SDLT, rent on a lease is taxed by reference to its net present value (NPV), not by simply adding up all the rent due over the lease term. This means future rent is discounted at 3.5% a year, and for years after the first five years, the calculation may use a statutory substitute rent instead of the actual rent payable under the lease.

• NPV treats rent due later in the term as worth less than the same amount due earlier.
• For years after year 5, SDLT may use the highest rent payable in any consecutive 12-month period during the first five years, rather than the actual later rent.
• In the example, years 6 to 10 use £8,000 a year for NPV purposes, even though the lease rent rises from £9,000 to £11,000.
• Using the 3.5% discount rate, the example produces an NPV of £57,192.25, compared with total contractual rent of £80,000.
• This substitution affects only the SDLT calculation and does not change the rent the tenant must actually pay under the lease.
• When checking lease rent for SDLT, it is important to review the first five years carefully and identify the correct figure required by the legislation.

Scroll down for the full analysis.

How SDLT works out the net present value of rent on a lease

This page explains how stamp duty land tax calculates the net present value, or NPV, of rent under a lease. This matters because SDLT on lease rent is not based simply on adding up all the rent due over the term. Instead, the rent is discounted year by year, and special rules can replace the actual later rent with a different figure.

What this rule is about

For SDLT, rent under a lease is charged by reference to its net present value. NPV is a discounted figure. In simple terms, rent payable later in the lease is treated as being worth less than the same amount payable earlier.

The source material gives a worked example of a 10-year lease with changing annual rent. It also highlights an important rule for years after the first five years of the term. For NPV purposes, the rent used for those later years is not always the rent actually payable under the lease. Instead, a statutory substitute figure may be used.

What the official source says

The example lease runs for 10 years. The rent stated in the lease is:

• Year 1: £4,000
• Year 2: £5,000
• Year 3: £6,000
• Year 4: £7,000
• Year 5: £8,000
• Year 6: £9,000
• Year 7: £9,500
• Year 8: £10,000
• Year 9: £10,500
• Year 10: £11,000

To calculate NPV, each year’s rent is discounted using a 3.5% annual rate. The discounted amounts are then added together.

However, for years 6 to 10, the example does not use the actual rent payable in those years. Instead, it uses £8,000 for each of those years. That is because £8,000 is the highest rent payable in any consecutive 12-month period during the first five years of the lease. The source says this replacement applies for NPV purposes only, and refers to Schedule 17A paragraph 7 to the Finance Act 2003.

Using that method, the total NPV is £57,192.25, rounded in the text to £57,192. This is lower than the total contractual rent over the term, which the source states as £80,000.

What this means in practice

The practical point is that SDLT on lease rent is not calculated by simply looking at the total rent written into the lease. Two adjustments are taking place.

• First, future rent is discounted, so later payments count for less in the NPV calculation.
• Second, for years after the first five years, the legislation may require you to ignore the actual later rent and use a substitute figure instead.

In the example, the actual rent rises steadily after year 5. But for years 6 to 10, the SDLT calculation uses £8,000 each year, not the higher contractual rents. That produces a lower NPV than would arise if the actual later rents were used.

This does not change what the tenant must actually pay under the lease. It changes only the figure used to calculate SDLT on rent.

How to analyse it

If you are checking the SDLT position for lease rent, the source material suggests this approach:

1. Identify the rent payable in each year under the lease.
2. Look carefully at the first five years of the term.
3. Find the highest rent payable in any consecutive 12-month period within those first five years.
4. For years after year 5, consider whether that figure replaces the actual later rent for NPV purposes.
5. Discount each year’s relevant rent using the 3.5% rate shown in the source.
6. Add the discounted figures together to reach the NPV.

The key question is not just “what rent does the lease require in year 8 or year 10?” It is also “what rent figure does the SDLT legislation require me to use for those years when calculating NPV?”

Example

Illustration based on the official example:

A tenant takes a 10-year lease. The rent starts at £4,000 in year 1 and rises each year to £11,000 in year 10. A reader might assume SDLT should be based on the full rising rents across the whole term. That is not how the example works.

For years 1 to 5, the actual rents of £4,000, £5,000, £6,000, £7,000 and £8,000 are used and discounted.

For years 6 to 10, the calculation does not use £9,000, £9,500, £10,000, £10,500 and £11,000. It uses £8,000 each year instead, because that is the highest rent in any consecutive 12-month period during the first five years.

After discounting each year’s figure at 3.5% and adding them together, the NPV comes to £57,192.25.

Why this can be difficult in practice

The official example is helpful, but there are a few points that can cause confusion.

• The NPV figure is not the same as the total rent payable under the lease. People often expect those figures to match. They do not.
• The rent used for later years may differ from the rent actually payable under the lease. That can seem counterintuitive unless you know the statutory rule.
• The source example appears to contain internal inconsistencies in the table. The narrative says years 6 to 10 use £8,000, and the NPV figures shown for those years match that approach, even though the lease rents listed earlier are higher. In practice, the explanation below the table is the important point: the substituted £8,000 figure is used for NPV purposes only.
• Care is needed in identifying the highest rent payable in any consecutive 12-month period in the first five years. That is a factual exercise based on the lease terms.

Where the rent pattern is more complicated than a simple annual increase, the analysis can become more technical. The same is true if the lease has stepped rents, irregular review dates, or periods that do not align neatly with lease years.

Key takeaways

• SDLT on lease rent is based on net present value, not simply the total rent payable over the term.
• Later rent is discounted, so future payments count for less in the calculation.
• For years after the first five years, the rent used for NPV may be a statutory substitute figure rather than the actual rent payable under the lease.

This page was last updated on 24 March 2026

Useful article? You may find it helpful to read the original guidance here: Manual Calculation Example of Net Present Value for Ten-Year Lease Rent

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