Look up the location of a central office by prefix. Country codes,City Code,Area Code,Dialing Code,Travel with your heart is Usefull for your heart in all countries. One Click Unbrick For Windows. Area Codes List. The following is a complete telephone area codes list of the United States. The map and locations information is available by clicking the specific. Unknown phone numbers, reverse lookup phone numbers in Texas and reviews of called number of area code 210 6702 2106702. CFR Chapter V Wage and Hour Division, Department of Labor. Annulment or Withdrawal of Certificates for the Employment of. Student Learners, Apprentices, Learners, Messengers, Handicapped Persons. Student Workers, and Full Time Students In Agriculture or In Retail or Service. Establishments At Special Minimum Wage Rates. Telephone numbering plan Wikipedia. A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, reachable by a system of destination code routing. Telephone numbering plans are defined in each of administrative regions of the public switched telephone network PSTN and they are also present in private telephone networks. Area Code Usa' title='510 Area Code Usa' />Area Codes List. Time Zones. New area codes through 200 4. Time Management Software. Time zone key PPacific, MMountain, CCentral, EEastern, AAtlantic. For public number systems, geographic location plays a role in the sequence of numbers assigned to each telephone subscriber. Numbering plans may follow a variety of design strategies which have often arisen from the historical evolution of individual telephone networks and local requirements. A broad division is commonly recognized, distinguishing open numbering plans and closed numbering plans. Many numbering plans subdivide their territory of service into geographic regions designated by a prefix, often called area code, which is a set of digits forming the most significant part of the dialing sequence to reach a telephone subscriber. The International Telecommunication Union ITU has established a comprehensive numbering plan, designated E. It is an open numbering plan, however, imposing a maximum length of 1. The standard defines a country calling code country code for each state or region which is prefixed to each national numbering plan telephone number for international destination routing. Private numbering plans exist in telephone networks that are privately operated in an enterprise or organizational campus. Such systems may be supported by a private branch exchange PBX which controls internal communications between telephone extensions. In contrast to numbering plans, which determine telephone numbers assigned to subscriber stations, dialing plans establish the customer dialing procedures, i. Even in closed numbering plans, it is not always necessary to dial all digits of a number. For example, an area code may often be omitted when the destination is in the same area as the calling station. North American Numbering PlaneditThe North American Numbering Plan is a closed numbering plan,23 that prescribes ten digits for each complete destination routing code, including a three digit area code followed by a three digit exchange and then four more digits. Other countries with open numbering plans use variable length numbers in some, such as Finland, subscriber numbers may vary in length even within an exchange. In early telephone systems, connections were made in the central office by switchboard operators using patch cords to connect one party to another. A telephone call was initiated by operating a magneto hand generator, usually integral to the customer telephone, to alert the central office operator by the ringing of a switchboard bell or the activation of a drop. In response, the operator inserted a patch cord into the corresponding line jack and assisted the customer by voice. The other end of the patch cord connected the caller to the destination telephone line. If the destination party belonged to another exchange, the operator established a connection to that exchange where another operator completed the call setup. As technology advanced, automatic electro mechanical switches were introduced and telephones were equipped initially with rotary dials for pulse dialing and then Touch Tone key pads in the 1. For telephone subscribers, prior to widespread use of area codes and the 1. GLadstone 7 an exchange in the Chicago area, which was 4. Subscribers needed only 7 digits to make calls within their area. In the United States and Canada, area codes were first allocated in 1. Some large cities used them soon after as operator routing codes for connecting long distance telephone calls between toll switching centers. The first customer dialed long distance calls were possible in Englewood, NJ in 1. By ca. 1. 96. 6, the system was implemented fully in both countries5 and users of the telephone system needed to learn their own area code. The Bell System organized the numbering plan to minimize the cost of providing automatic dialing to large population centers, as calls that crossed area code boundaries were required to be switched by special toll switching systems. Thus, the number of toll calls long distance in common parlance calls were minimized by well designed geographical areas. Tributary routes were placed into the same area as the major toll center. States that were anticipated to require more than about 5. In contrast to the area code, the second digit of the three digit exchange code was never 0 or 1, thus affording a simple rule for recognition of whether a user was dialing a full ten digit telephone number or merely dialing within the local area code using seven digit dialing. Toll operators were able to differentiate between the two types of areas from the middle digit of the area code when a routing operator had to be consulted. By the 1. ESS equipment and the previous area code logic was no longer necessary. The demand for telephone numbers was increasing rapidly, and the remaining n. This area code scheme was abandoned, with the result that area codes and central office codes could not necessarily be automatically distinguished by the switching equipment. The solution was to require the dialing of a preceding 1 for calls across area codes, in which case the equipment expected 1. If the first digit dialed was not a 1, only 7 digits were expected and the area code was inferred from the originating subscribers area code. For a short while, in some area codes, one could enter the full 1. The rising popularity of fax machines and pagers required far more telephone numbers than were anticipated in the design of the numbering system. As a remedy, the restrictions on the format of area codes were eased. Since 1. 99. 5, over 3. North American Numbering Plan. Some areas used area code splits, by which an existing numbering plan area NPA was split into multiple divisions each assigned a new area code. Thus, many businesses were required to reprint business stationery, catalogs, and directories. Area code splits were often contested as to which area could keep the existing code, which usually fell to the largest city. For example, 3. 05 was split in 1. Miami and Fort Lauderdale area. Dade County Miami Dade kept 3. Broward County Fort Lauderdale area had to change to 9. Another method was using area code overlays, which avoided renumbering existing stations. An overlay is a new area code that covers the same geographical area as an existing code. Over 7. 5 overlays have been introduced since 1. Area code overlays invariably require ten digit dialing of telephone numbers in the numbering plan area. Internet telephony services are not tied to physical locations and area codes often no longer correspond to the physical location of the provider, nor the subscriber. Number structureeditMost national telephone administrations issue telephone numbers that conform to the E. E. 1. 64 conformant telephone numbers consist of a country calling code and a national telephone number. National telephone numbers are defined by national or regional numbering plans, such as the European Telephony Numbering Space, the North American Numbering Plan NANP, or the UK number plan.