UK Commercial SDLT Calculator (England & Northern Ireland)
Estimate stamp duty for non-residential and mixed-use property transactions. You can calculate freehold/premium SDLT and, for leases, the rent element based on an NPV estimate.
Rates used: 0% up to £150,000, 2% from £150,001 to £250,000, and 5% above £250,000 for non-residential/mixed-use consideration. Lease rent estimate uses 1% above £150,000 NPV with a 3.5% discount assumption.
How commercial stamp duty works
When buying commercial property in England or Northern Ireland, tax is generally calculated under non-residential Stamp Duty Land Tax (SDLT) rules. This applies to offices, retail units, warehouses, industrial sites, agricultural land, and mixed-use property.
The key idea is that SDLT is charged in slices, not one single rate on the whole purchase price. That means each part of the price is taxed at the band rate that applies to that part.
Current non-residential SDLT bands
- 0% on the portion up to £150,000
- 2% on the portion from £150,001 to £250,000
- 5% on the portion above £250,000
Lease transactions: premium and rent can both be taxed
For a new lease, tax can be due on two separate pieces:
- Any lease premium (calculated using the same commercial bands above)
- The Net Present Value (NPV) of rent (typically 0% up to £150,000 NPV, then 1% above that)
This calculator handles both parts so you can get a quick estimate before speaking with your solicitor or adviser.
How to use this commercial property stamp duty calculator
For a purchase or premium only
Select Freehold or lease premium purchase, enter the price, and click calculate. You will see total SDLT and a band-by-band breakdown.
For a new lease
Select New lease (premium + rent), enter any premium, annual rent, and the lease term in years. The tool estimates:
- Tax on premium
- Estimated NPV of rent
- Tax on rent NPV
- Total estimated SDLT due
Worked examples
Example 1: Buying a small warehouse for £400,000
- 0% on first £150,000 = £0
- 2% on next £100,000 = £2,000
- 5% on remaining £150,000 = £7,500
Total SDLT: £9,500
Example 2: Office lease with no premium, £60,000 annual rent, 10-year term
The calculator estimates discounted rent NPV and then applies the 1% lease-rent rule above £150,000 NPV. This gives a practical planning number while keeping assumptions transparent.
What can change your final bill
- Multiple linked transactions: HMRC may combine values.
- Reliefs: Some acquisitions may qualify for reliefs, reducing SDLT.
- Complex lease structures: Turnover rents, stepped rents, and reviews can alter NPV treatment.
- Mixed-use classification questions: Correct classification is essential.
- Corporate structuring: Transactions through companies may involve wider tax implications.
Commercial acquisition checklist
- Confirm property classification early (commercial, mixed-use, or other).
- Build SDLT into your full acquisition budget (legal fees, valuation, financing, VAT, fit-out).
- For leases, model different rent scenarios and term lengths.
- Ask your solicitor for an SDLT filing timeline before completion.
- Keep written records supporting any relief or classification position.
Final thoughts
A reliable stamp duty estimate helps prevent under-budgeting and improves negotiation confidence. Use this calculator for quick planning, then verify numbers with a qualified professional before exchange or completion.