A non-profit organization is defined as a legal entity established for achieving public or general interest of the individual or group. It follows that the purpose of the organization is not to make profits. The aim of this paper is to show the accounting and business of non-profit organizations in this case of the Croatian Society for Non-Destructive Testing. When compiling the paper not only Croatian literature was used, but also English and certain websites. The society is liable to pay value added tax because the value of the supply of goods or services performed in the previous calendar year exceeded 230,000.00 kunas. Since the society also carries out economic activities, it is liable for corporate tax and applies a double-entry bookkeeping. The Rulebook of non-profit accounting and chart of accounts arranges the content, layout and the appropriate use of the chart of accounts that the society applies. The association is registered in the Register of non-profit organizations kept by the Ministry of Finance because all the organizations that are not registered in the Register, can penalized under the Law on financial operations and acconunting of non-profit organizations.