FACT SHEET Future Changes in Telephone Numbering Several important changes will affect the North American Numbering Plan during the next few years. These changes will require telephone companies to modify their network switches. They will also require some users to modify their customer premises equipment. The equipment affected includes payphones and privately owned switchboards (generically known as private branch exchanges or PBXs). This Fact Sheet has been prepared to answer the most frequently asked questions about upcoming changes in telephone numbers. It also provides sources of further information and assistance. Interchangeable Area Codes Currently, the second digit of an area code is always "0" or "1". All usable three-digit numbers in this format have been assigned as area codes. Beginning in 1995, new area codes will have numbers other than "0" or "1" as the second digit. As a result, area codes will have the same format as the central office codes that appear at the beginning of local telephone numbers--hence, the term "interchangeable" codes. Three interchangeable area codes have been assigned for service during early 1995. These new area codes will be placed in service in Alabama (334), Washington State (360), and Arizona (520). Some parts of the telephone network--including both telephone company switches and customer equipment--were not designed to handle interchangeable codes. When a call to an interchangeable area code is attempted from such equipment, the call will not be routed correctly. Therefore, this equipment must be reprogrammed, modified, or replaced in order to handle the dialing of interchangeable area codes. New Dialing Procedures Dialing procedures have traditionally been determined by local telephone companies and state public utility commissions. Consequently, they are not uniform, especially for toll calls that originate and terminate within the same area code. Over a period of many years, three basic dialing procedures have evolved for toll calls that do not cross an area code boundary. In some states, such calls are made simply by dialing a seven-digit number. In other states, these calls are placed by dialing "1" as a toll indicator, followed by the seven-digit number. In still other states, toll calls within the same area code are placed by dialing "1" plus ten digits (the local area code plus the seven digit number). When interchangeable codes are activated in 1995, the prefix "1" will be used to indicate that the call is longer than seven digits. This means that the "1 plus 7" method of dialing toll calls within the same area code will no longer be feasible. Each state that used "1 plus 7" dialing has selected one of the other two dialing options. Some states have already completed the change and others are in the process of doing so. The use of "1" as an indicator of ten-digit calls means that, in most areas, systems cannot rely on a leading "1" as a toll indicator. PBXs or other switches that have been programmed to block toll calls based on the use of "1" as a toll indicator will need to be altered. Conversion to 101XXXX Access Codes Callers sometimes reach long distance carriers by dialing carrier access numbers in the format 10XXX (where "XXX" represents a carrier's three-digit identification code). AT&T's code is 288, MCI's is 222, etc. Thus, customers can reach AT&T by dialing 10288, reach MCI by dialing 10222, etc. Because almost all three-digit identification codes have been assigned, four-digit identification codes will be assigned in 1995. Carriers with four-digit identification codes will be reached by dialing 101XXXX. Under current law, new equipment manufactured for use by aggregators (PBXs or key systems used by hotels, motels, hospitals, universities, payphones, and others that provide telephones for "transient" users) must be capable of processing 10XXX access code dialing. There are also regulatory deadlines to allow 10XXX dialing in older, non-conforming equipment. Newly manufactured equipment should have the capability of processing 101XXXX dialing, but some payphones and other older equipment will not be able to complete calls to 101XXXX numbers. During a transition period, both 10XXX and 101XXXX access codes will be used. At the end of the transition period, all access codes will use the 101XXXX format. The transition period will provide owners of non-conforming equipment with time to modify, reprogram, or replace that equipment. However, users of such equipment will not be able to reach carriers with the new four- digit identification codes until modifications are made. The FCC has proposed a transition period of six years. Thus, users may have several years to make the necessary changes. The date when such changes will become mandatory has not yet been established. Longer International Telephone Numbers Under international agreements, international telephone numbers are now limited to 12 digits. Beginning in 1997, the maximum permissible length will be increased to 15 digits. Although there are no plans to increase the length of telephone numbers in the United States, Germany has announced its intention to lengthen its numbers. Several other countries are also likely to do so. When the length of international telephone numbers is increased, customer premises equipment will have to store and process the longer numbers. Where to Go for More Help For questions regarding specific customer premises equipment and what must be done to ensure readiness to process the new numbers, users should first consult the manufacturers or equipment suppliers. Additional information is also available from the following sources: *** The North American Numbering Plan is administered by Bell Communications Research. The administrator has prepared a report, Status of Numbering in the NANP Served Area, that provides more detail on each of the coming changes and includes the dialing plan in each state. The report is available without charge from: Claudette Keith North American Numbering Plan Administration Bell Communications Research Room 1E240 290 West Mt. Pleasant Avenue Livingston, New Jersey 07039-2798 201 740-6792 201 740-6860 (FAX) Questions on interchangeable area codes, dialing plans, and international telephone numbers can be addressed to: Garry Benoit North American Numbering Plan Administration Bell Communications Research Room 1B227 290 West Mt. Pleasant Avenue Livingston, New Jersey 07039-2798 201 740-4592 201 740-6860 (FAX) Questions on the expansion of carrier identification codes can be addressed to: Jim Deak North American Numbering Plan Administration Bell Communications Research Room 1B227 290 West Mt. Pleasant Avenue Livingston, New Jersey 07039-2798 201 740-4594 201 740-6860 (FAX) *** The vast amount of information necessary for routing calls throughout the telephone network is maintained by Bellcore's Traffic Routing Administration. The information is contained in large data bases and most can be reached through on-line computer access. Much of the information can also be purchased in a variety of formats (paper, tape, microfiche, and CD-ROM). A catalog describing the products available can be obtained from the Traffic Routing Administration Hotline at 201 740-7500. For more information, contact: Donald Baechler Traffic Routing Administration Bell Communications Research Room 1E235 290 W. Mt. Pleasant Ave Livingston, N.J. 07039-2798 201 740-7575 201 740-6999 (FAX) *** Local telephone companies and long distance carriers have been preparing for the coming changes. The United States Telephone Association has prepared several information bulletins that are available without charge. These publications can be obtained from, and questions about the telephone network can be addressed to: Dennis Byrne Executive Director Operations and Engineering United States Telephone Association Suite 600 1401 H Street N.W. Washington, D.C. 20005-2136 202 326-7296 202 326-7333 (FAX) *** The North American Telecommunications Association represents both suppliers and users of telecommunications equipment. They have prepared a publication called The North American Numbering Plan: A Guide to Preparing for the New Number Formats. This publication can be obtained for a charge of $25.00 by calling 800 538-6282, Ext 260. Questions can be addressed to: Mary Bradshaw Director, Industry Relations North American Telecommunications Association Suite 550 2000 M Street N.W. Washington, D.C. 20036 202 296-9800, Ext. 210 202 296-4993 (FAX) *** All of the publications referred to above are available in the Public Reference Room operated by the Commission's Industry Analysis Division. Questions may be addressed to the Commission's staff at: Industry Analysis Division 1250 23rd Street N.W. Washington, D.C. 20554 202 632-0745 202 632-1411 (FAX)