At the 1903 International Telegraph Conference in London, telephone regulations finally became an important part of the work of the Union. A special Committee was established at the conference with the sole purpose of drawing up regulations for the international telephone service, which had grown to the point where positive rules were necessary. The original five paragraphs of rules introduced at the Telegraph Conference of 1885 (Berlin) were expanded to fifteen articles which included over sixty paragraphs.

This administrative conference also revised the telegraph regulations and the tables of international tariffs.