STAMP DUTY CALCULATOR You must pay Stamp Duty Land Tax (SDLT) if you buy a property or land over a certain value in England and Northern Ireland. Try our simple calculator to give you an idea how much Stamp Duty you will have to pay… OFFICIAL GOVERMENT GUIDELINES Enter the purchase price £ When will your mortgage complete? before July 2021 1 July to 30 Sept 2021 1 Oct 2021 onwards What type of mortgage is it? Normal Residential Mortgage? First Time Buyer Mortgage? Buy to Let and Second Property? Commercial Freehold? Commercial Leasehold?