On September 16, 1946 the United States government requested that the Bureau of the International Telecommunication Union invite members of the Union to a plenipotentiary conference in Atlantic City. The International Telecommunications Conferences took place in Atlantic City beginning with the International Radio Conference, which convened on 15 May 1947, and the International Telecommunication Conference, which was held simultaneously beginning on 1 July 1947. One of the first actions of the International Telecommunication Conference was to approve the Rules of Procedure as well as assess the participation of a number of uninvited countries. In particular, Spain was not admitted to any of the Atlantic City conferences while under the rule of Franco.

Changes were made to the Frequency Allocation Table including the decision to identify a place on the frequency spectrum for radionavigational service. In addition, the Cairo Regulations would be broadened to include allocations for aeronautical mobile service and high frequency broadcasting. A band was assigned for the development and use of experimental long distance radionavigation systems.A frequency was assigned for maritime mobile radio-telephone to be used for calling and distress purposes. Finally, a decision was made to relocate bands available to amateurs by moving them from the worldwide band to the 30-10,500 Mc/S band.

The International Frequency Registration Board (IFRB) was created to act as an administrative body to regulate the use of frequencies. It was created at the International Radio Conference and approved by the International Telecommunication Conference. The creation of the IFRB introduced an entirely new type of administrative body and new concept in the regulation of radio to the Union. The IFRB would create a master frequency list that would enable the notification and registration of frequency use to be tracked. In addition, the IFRB would notify member countries of new registrations giving them an opportunity to raise concerns and objections. The registration of a new frequency would be completed if it conformed with all provisions of the Regulations. A working group was created to draw up procedures for the IFRB including its duties: the notification and registration of frequencies, undertaking studies and recommendations on frequency usage and the cancellation of frequency recordings. The IFRB would have eleven members from four areas of regional representation: Americas, Western Europe and Africa, Eastern Europe and North Asia and the rest of the world. Furthermore, the members of the IFRB were to be free of outside influence. They were not on the board to represent their country, but an international public trust. The IFRB would be brought into existence on 1 January 1948; however, the representatives for the IFRB were elected at the conference and held their first meeting on September 30, 1947. A committee convened and examined the frequencies that were in use, but also the frequencies that were needed. This committee also examined and determined the directives for the International Frequency List. It was decided that work on a new International Frequency List would continue after the conference. Following the International Radio Conference the IFRB would work with the Provisional Frequency Board to create a new International Frequency List that would be compiled based on engineering principles.

The use of Class B (Spark) emissions was forbidden except for emergency use aboard ships, lifeboats and other survival craft equipment. Article 33 of the Regulations introduced two important changes: provisions were included that would allow aircraft to use a certain number of frequencies in the maritime service; and, the maritime frequency bands would be sub-divided into three categories: calling, passenger-ship working and cargo ship working. Regarding procedures in aeronautical service, it was decided that the International Civil Aviation Organization and other international aeronautical organizations would assume the responsibility for procedures and regulations related to aeronautical communication. However, ITU would continue to maintain general procedures regarding distress signals. The rates for aeronautical service were raised so that the cost of radiotelegraph rates for aircraft would conform with ship charges.