ITU-T Recommendations

ITU-T Rec. E.164 describes the international public telecommunication numbering plan. ITU-T Rec. E.190 describes the general principles to be utilized in the assignment of ITU-T E-series international numbering resources. This Recommendation describes the procedures and criteria for the reservation, assignment and reclamation of E.164 country codes and associated Identification Code (IC) assignments. The criteria and procedures are provided as a basis for the effective and efficient utilization of the available E.164 numbering resources. Such assignments require a collaborative effort between the TSB and the appropriate ITU-T Study Group to endeavour to ensure that the assignments meet the needs of the telecommunication community. The development of these criteria and procedures are in accordance with the principles contained in ITU-T Rec. E.190 and the numbering plan formats detailed in ITU-T Rec. E.164. While processing E.164 resource applications, any conflicts between these Recommendations that are identified will be resolved by the following: Those statements contained in ITU-T Rec. E.190 take precedence over ITU-T Rec. E.164, and those statements contained in ITU-T Rec. E.164 take precedence over this Recommendation.The TSB assigns and reclaims E.164 country codes for geographic areas, global services and for Networks. It is also responsible for the assignment and reclamation of Identification Codes (ICs) for Networks. The assignment of subsequent digits are normally not the purview of the ITU-T, but are the purview of the assignee. However, there may be unique circumstances by which it is jointly agreed by the TSB and the appropriate ITU-T Study Group that subsequent digits are to be centrally administered, e.g., UIFNs.