The Post and Telecommunications Surveillance Service is an independent service for surveilling post and telecommunications in Switzerland. Upon request by a Swiss law enforcement authority, it conducts inquiries. In doing so, the service is not bound by instructions of other authorities but has authority to give instructions to telecommunication providers. The Surveillance Service is administratively affiliated to the IT Service Center of the Federal Department of Justice and Police (ISC-FDJP, cf. Art. 3 VÜPF/OSCPT).

The Swiss Code of Criminal Procedure (StPO/CPP) lists the crimes which qualify for post and telecommunications surveillance and for findings to be used in court. The law also stipulates under what conditions post or telecommunications surveillance is admissible (Art. 269(2) CCP and Art. 70(2) Code of Military Criminal Procedure). It is important to note that surveillance mandates are subject to judicial approval. Apart from criminal proceedings, post and telecommunications surveillance may be ordered to search for missing persons (Art. 3 BÜPF/LSCPT). In addition, the law provides for the principles that govern the procedure and the execution of the emergency search of a person's whereabouts and regulates the jurisdiction of the authorities involved.

The Post and Telecommunications Surveillance Service compensates telecommunication providers for expenses they incur in retrieving data. Law enforcement authorities requesting data are charged with these costs in the form of a fee. A table of fees is contained in the Regulation on Fees and Compensation for Post and Telecommunications Surveillance Operations (SR 780.115.1).