Stamp duty is what increases the costs of buying and selling property. It is possible to avoid stamp duty and to do so legally. One of the main ways of how to avoid stamp duty is to pay less money for the property you are buying than what it is actually worth. To do this, you will have to choose your property carefully. Not every seller will be willing to negotiate a low enough price so that you can avoid stamp duty. You may have to find a seller who has had a property for sale for a long while in order to negotiate such a price.