The aim of social security, known as a system is to protect the insured against social risks. In accordance mandatory insurance principle adopted in our social security system and the principles of direct registration, insurance arises automatically when starting work. However, the service detection actions is very important for insurance periods that are not notified by the employer or determined by the Institution in our country where the social security system with social contributions has been adopted, In this case, both working case and insurable earning on social security contributions are determined. However, the procedural principles adopted by the high court for both determinations are different. In this study, the proof of insurable earning and real wages determined as a natural result in the service detection actions and judicial decisions will be examined.