We give here the background and basis for the new international electrical reference standards of voltage and resistance that are to come into effect worldwide starting on 1st January 1990. Founded on the Josephson and quantum Hall effects, respectively, these new reference standards will improve significantly the international uniformity of electrical measurements and their consistency with the SI. 1 The members of the CCE Working Group on the Josephson Effect were R. Kaarls (VSL), B. P. Kibble (NPL), B. N. Taylor (NIST), and T. J. Witt, Coordinator (BIPM). The members of the CCE Working Group on the Quantum Hall Effect were F. Delahaye (BIPM), T. Endo (ETL), 0. C. Jones (NPL), V. Kose (PTB), B. N. Taylor, Coordinator (NIST), and B. M. Wood (NRC). (See the Appendix for the laboratory abbreviations used throughout this paper.