Social security is the system that protects individuals from the pyhsiological, occupational and socio-economic risk. For the correctly functioning of social security systems, premium income should be high. System is becoming more problematic as between income-expenditure scissors is opened part way. Throughtout the historical process in Turkey, Social security instutions have been founded. However, in time there have been financial problems in terms of becoming operative. Ageing of the population, early retirement, unemployment and increase in health expenses are main problems. In addition to all these causes, another essential reason is informal employment. Because informal employment causes to reduction in incomes and social security expenses rise. Depending on informal employment, rising expenses have negative effect on distribution of income, gross domestic product and loan contracted. Prior to law of 5510, very few inspectors tried to deal with informal employment. However, there has been no success. Today, this is carried out by Social Security inspectors and Social Security supervisors. Particularly with the new employment of Social security Supervisors a more active inspection have started. In this study, the role of the audit -consequently, in the reduction of social security deficits- has been stated and the results of the inspections carried out in Manisa have been evaluated.