With this paper is shown the importance of running a business and the importance of entrepreneurs adaptability in his environment when problems appear. The work structure includes units important for the concept of expenses and entrepreneurs attitude. In the beginning itself there are: conceptual definition of the expenses, usage of expenses in business transactions, models of managing expenses, how does a business firm change when the scale of the production changes. Subsequently there is specified how does a business firm operate, their expenses management, business firms expenses policy, analysis of the expenses and the chain of the value. The other part of the paper comprises of: distribution of expenses in business transactions and the attitudes of the entrepreneurs and we have given an example of the business transaction analysis and the behaviour of the expenses in the business firm Nexe Grupa d.d. Extra attention in this paper is directed on the expenses and business undertakings as a vital business part and the secret of success in business of every entrepreneur.