Most commercial stamp duty calculators only do half the job. On a freehold purchase there is one calculation. On a new lease there are two, because the rent is taxed separately from any premium, and the second one is the part that catches occupiers out. This does both.
Commercial stamp duty calculator
Non-residential SDLT for England and Northern Ireland. Freehold purchases, new leases including the net present value of rent, and mixed use. Nothing is sent anywhere and nothing is stored.
1. The transaction
Where the seller or landlord has opted to tax, SDLT is charged on the VAT inclusive figure. This is one of the most commonly missed points in a commercial deal.
How the price is taxed
A new lease means two calculations
On a freehold purchase, stamp duty is charged on the price in slices. On a newly granted lease it is charged twice over: once on any premium you pay for the lease, and separately on the net present value of the rent across the whole term. The two figures are worked out under different band tables and then added together.
The rent calculation is the one people miss, because there is no obvious purchase price to focus on. A lease with no premium at all still produces a stamp duty bill if the rent is high enough or the term is long enough. On a 25 year lease at £100,000 a year the net present value runs to over £1.6 million and the duty is close to £15,000, payable at the start.
How the net present value of rent works
The rent for each year of the term is discounted back to today at a fixed statutory rate of 3.5% a year, and the discounted figures are added up. That total is the net present value, and stamp duty is charged on it at nil up to £150,000, 1% on the slice from £150,000 to £5 million, and 2% above that.
Only the first five years use the actual rent. For year six onwards the rules assume the rent stays at the highest amount payable in any twelve month period during those first five years. That is why the calculator asks separately for the highest rent in the first five years. If your lease has a stepped increase or a review inside the first five years, that higher figure is carried forward across the whole remaining term, which can add a surprising amount to the bill.
A practical consequence: pushing a rent review just outside the first five years, rather than inside them, can reduce the stamp duty on a long lease. That is a point to raise with your solicitor at heads of terms stage, not after the lease is signed.
The £1,000 rent trap
If you pay a premium for a new commercial lease and the annual rent is £1,000 or more, the nil rate band on the premium is not available. The first £150,000 of premium is charged at 2% instead of nothing. On a £100,000 premium that is a £2,000 bill where an identical deal with a peppercorn rent would pay nothing at all.
Set the rent below £1,000 in the calculator and watch the duty on the premium disappear. It is a genuine cliff edge rather than a taper, and it is worth knowing about before the rent is agreed.
VAT counts towards the price
Where the seller or landlord has opted to tax, VAT is charged on top of the price or rent, and stamp duty is then charged on the VAT inclusive total. On a £500,000 commercial building with VAT, the duty is worked out on £600,000, which pushes the bill from £14,500 to £19,500. The £5,000 difference is real money and it does not appear in a calculator that ignores VAT.
The same applies to rent. If VAT is charged on the rent, the net present value is calculated on the VAT inclusive rent.
When residential property is taxed at commercial rates
Two situations matter here. A mixed use property, such as a shop with a flat above, is treated as non-residential in its entirety, so the whole price goes through the commercial bands. And where six or more dwellings are bought in a single transaction, the buyer may treat them as non-residential, which on a portfolio purchase is usually the cheaper answer.
Note that Multiple Dwellings Relief, which used to help on purchases of two to five dwellings, was withdrawn for transactions completing on or after 1 June 2024. Older guides and calculators still reference it.
England and Northern Ireland only
Stamp Duty Land Tax applies in England and Northern Ireland. Scotland charges Land and Buildings Transaction Tax and Wales charges Land Transaction Tax, both with their own bands and their own treatment of leases. Do not use this calculator for a property in Scotland or Wales.
You have fourteen days
An SDLT return has to be filed and the tax paid within fourteen days of the effective date of the transaction, which is usually completion. That is a short window, and interest and penalties run from day fifteen. Your solicitor normally handles the return, but the money has to be available, which is a funding question rather than a legal one.
What this does not cover
- Any relief or exemption, including group relief, charities relief, sale and leaseback relief and transfers involving partnerships.
- Linked transactions and connected party rules, where several purchases are aggregated and taxed as one.
- Lease extensions, surrenders and regrants, and holding over at the end of a term, all of which have their own treatment.
- Variable or turnover rents, where the rent has to be estimated and the return revisited later.
- Residential rates, the higher rates for additional dwellings, and the surcharge for non-resident buyers.
- Scotland and Wales.
Funding the tax as well as the property
Stamp duty cannot be borrowed against the property itself, because a lender advances against value and the tax adds none. On a £450,000 commercial purchase the duty is £12,000, and that sits on top of the deposit and the legal costs as cash you need on completion day. It is a common reason a deal that looked comfortable on paper gets tight at the end.
Our commercial mortgage affordability calculator shows the maximum loan the property will support on both lender tests, which tells you the deposit, and from there the full day one cash requirement including this tax. Where the purchase is at auction and the timescale is short, the bridging loan cost calculator prices the short term route.
Get the purchase funded properly
We arrange the finance rather than the conveyancing, but we see the same avoidable problem repeatedly: a buyer who has budgeted for the deposit and not for the tax, the fees and the VAT. Send us the deal and we will set out the full day one cash requirement alongside what the lending looks like.
Or try our other calculators.
This calculator is provided for illustration and general information only. It is not tax, legal or financial advice, and it is not a substitute for advice from your solicitor or accountant, who should confirm the stamp duty position before you exchange. Rates and rules are those understood to apply to non-residential Stamp Duty Land Tax in England and Northern Ireland and should be checked against current HMRC guidance before you rely on them. Reliefs, linked transactions and partnership rules are not modelled. Bolton Business Finance Ltd is a commercial finance broker and not a lender, and is not authorised or regulated by the Financial Conduct Authority. We arrange non-regulated, business purpose commercial finance only.