The Republic of South Sudan became independent on 9 July 2011 from Sudan and issued its first stamps on 13 July 2011. Only almost three months later, on 4 October 2011, did South Sudan become a member of the Universal Postal Union (UPU).Before independence, South Sudan used stamps issued by Sudan. The Directorate of Postal Services of the Ministry of Telecommunication and Postal Services is responsible for postal affairs in South Sudan
In the first months after Independence of South Sudan on 9 July 2011 and the start of selling of their own first stamps of the Republic of South Sudan to the public a few days later, the South Sudan postal authorities were also still selling their stock of stamps of Sudan, resulting in covers with mixed franking.