Calculating SDLT: Apportioning Rent for Leases with Part-Year Terms

SDLT on Lease Rent Where the Lease Term Includes Part of a Year

When working out SDLT on lease rent, an incomplete final year of the lease is not ignored and is not rounded up to a full year. Instead, the annual rent is apportioned by the number of days in that final part year, and that apportioned amount is included in the net present value calculation as the last part of the lease term.

• SDLT on the grant of a lease depends partly on the net present value of the rent over the lease term.
• If the lease runs for whole years plus an extra period, use full annual rent for each complete year and a daily apportionment for the final part year.
• For SDLT purposes, the incomplete period is always treated as falling at the end of the lease term.
• You should not ignore the extra days or months, and you should not treat them as a full extra year.
• A practical approach is to identify the total term, separate complete years from the remaining days, and apportion the annual rent for that final period.
• Care is needed where the lease wording is unusual or the rent changes during the term, as this can affect the wider SDLT calculation.

Scroll down for the full analysis.

SDLT on lease rent: how to deal with a lease term that includes part of a year

This page explains a narrow but important point in the SDLT calculation for lease rent. If a lease does not run for a whole number of years, the final part year is not ignored. Instead, the annual rent is apportioned by days for that part year when working out the net present value of the rent. This matters because SDLT on leases is based in part on the rent payable over the term, and even a short extra period can affect the calculation.

What this rule is about

When SDLT is calculated on the grant of a lease, one of the key figures is the net present value of the rent over the term of the lease. Many leases run for an exact number of years, but some do not. A lease might run, for example, for 5 years and 3 months, or 10 years and 10 days.

The issue here is how to treat that incomplete final year. The HMRC material addresses this directly: if the lease term includes a part year, the annual rent must be reduced to reflect only the number of days in that part year.

For SDLT purposes, that part year is treated as falling at the end of the lease term.

What the official source says

The official HMRC manual says that where the term of a lease includes a part year, the annual rent should be apportioned to the number of days in that part year. It also states that, for the purpose of calculating net present value, the part year will always be at the end of the lease.

In simple terms, the calculation assumes:

• full yearly amounts for each complete year of the lease, and
• a daily apportionment of the annual rent for the final incomplete year.

The source is dealing with the mechanics of the SDLT rent calculation. It is not changing the rent under the lease. It is telling you how to convert the lease term into figures that can be used in the SDLT formula.

What this means in practice

If a lease lasts for a whole number of years plus an extra period, you do not round up to a full year and you do not ignore the extra period. You work out how many days are in that final part year and apply that fraction to the annual rent.

This has a practical effect where:

• the lease term is expressed in years and days or years and months;
• the lease starts or ends on a date that does not produce a whole number of years; or
• the parties need an accurate net present value calculation for the SDLT return.

The point that the part year is always treated as being at the end matters because it standardises the calculation. You do not split the lease into an odd initial period and then whole years after that. For SDLT rent calculation purposes, the incomplete period is treated as the final slice of the term.

How to analyse it

A sensible way to approach the issue is:

• Identify the total term of the lease.
• Separate the term into complete years and any remaining part year.
• Count the number of days in that part year.
• Take the annual rent figure relevant to the calculation.
• Apportion that annual rent by reference to the number of days in the part year.
• Treat that apportioned amount as the rent for the final incomplete year when calculating net present value.

The key question is not whether the lease happens to begin or end part-way through a calendar year. The key question is whether the lease term itself contains an incomplete final year.

Example

This is an illustration of the method only.

Suppose a lease is granted for 5 years and 90 days at a fixed annual rent of £12,000. For SDLT rent purposes, you would generally treat this as:

• 5 complete years at £12,000 a year, and
• a final part year of 90 days, with the annual rent apportioned for those 90 days.

You would not treat the lease as 6 full years. You would also not ignore the extra 90 days. The 90-day amount is included as the final part of the term in the net present value calculation.

Why this can be difficult in practice

The rule itself is short, but applying it can still raise practical issues.

• The lease term must first be identified correctly. If the drafting is unusual, it may not be obvious how many complete years and extra days there are.
• The HMRC page here gives the principle, but not the worked arithmetic. The detailed effect depends on the wider net present value rules and the examples in the following manual pages.
• Where rent changes during the term, the broader SDLT lease-rent rules may need to be considered alongside this apportionment point.

The main risk in practice is not understanding the legal rule, but applying the lease term incorrectly or using the wrong annual rent figure in the wider SDLT calculation.

Key takeaways

• If a lease term includes less than a full final year, that period still counts for SDLT rent purposes.
• The annual rent is apportioned by days for that part year.
• For net present value calculations, the incomplete year is treated as falling at the end of the lease term.

This page was last updated on 24 March 2026

Useful article? You may find it helpful to read the original guidance here: Calculating SDLT: Apportioning Rent for Leases with Part-Year Terms

View all HMRC SDLT Guidance Pages Here